criyle/codenet-compile-errors huggingface dataset:
Language: C++

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>

using namespace std;



char s[105];
int b = 0;



int main()
{
	while(~scanf("%s",&s)){
		cout << s[0];
		memset(s, 0, sizeof(s));
	}
	cout << endl;


	system("pause");

}

Compiler output:
a.cc: In function 'int main()':
a.cc:19:17: error: 'memset' was not declared in this scope
   19 |                 memset(s, 0, sizeof(s));
      |                 ^~~~~~
a.cc:4:1: note: 'memset' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
    3 | #include <algorithm>
  +++ |+#include <cstring>
    4 | #include <string>
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main(){
  string s;cin>>s;
  string t="A";
  t+=substr(8,1);
  t+="C";
  cout<<t<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:6: error: 'substr' was not declared in this scope; did you mean 'strstr'?
    6 |   t+=substr(8,1);
      |      ^~~~~~
      |      strstr
Language: C

#include<stdio.h>
using namespace std;
#include<cstring>

int main(){
	char s[105];
	gets(s);
	int len = strlen(s);
	printf("%c%c%c\n",s[0],s[8],s[len-7]);
	return 0;
	}

Compiler output:
main.c:2:1: error: unknown type name 'using'
    2 | using namespace std;
      | ^~~~~
main.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    2 | using namespace std;
      |                 ^~~
main.c:3:9: fatal error: cstring: No such file or directory
    3 | #include<cstring>
      |         ^~~~~~~~~
compilation terminated.
Language: C++

#include<stdio.h>
using namespace std;
#include<cstring>

int main(){
	char s[105];
	gets(s);
	int len = strlen(s);
	printf("%c%c%c\n",s[0],s[8],s[len-7]);
	return 0;
	}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
    7 |         gets(s);
      |         ^~~~
      |         getw
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main(){
  string a,x,c;
  cin >> a >> x >> c;
  cout << "A"+x.at(0)+"C" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:22: error: invalid operands of types 'const char*' and 'const char [2]' to binary 'operator+'
    6 |   cout << "A"+x.at(0)+"C" << endl;
      |           ~~~~~~~~~~~^~~~
      |              |        |
      |              |        const char [2]
      |              const char*
Language: C++

include <bits/stdc++.h>
using namespace std;

int main() {
string s;
cin >> s;
char c = s.at(10);

cout << "A" << 'c' << "C" << endl;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include <bits/stdc++.h>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:5:1: error: 'string' was not declared in this scope
    5 | string s;
      | ^~~~~~
a.cc:6:1: error: 'cin' was not declared in this scope
    6 | cin >> s;
      | ^~~
a.cc:6:8: error: 's' was not declared in this scope
    6 | cin >> s;
      |        ^
a.cc:9:1: error: 'cout' was not declared in this scope
    9 | cout << "A" << 'c' << "C" << endl;
      | ^~~~
a.cc:9:30: error: 'endl' was not declared in this scope
    9 | cout << "A" << 'c' << "C" << endl;
      |                              ^~~~
Language: C++

#include "iostream"
#include "cstdio"
#include "cstring"
using namespace std;
 
const int maxn=10000000;
char ss[maxn];
 
int main(int argc, char* argv[])
{
	int n,i;
	scanf("%d",&n);
	getchar(); //过滤换行符
	while(n--)
	{
		gets(ss);
		for (i=0;i<(int)strlen(ss);i++)
		{
			if (i==0)       //判断第一个字符
			{
				if (ss[i]>='a'&&ss[i]<='z')
				{
					ss[i]-=32;
					printf("%c",ss[i]);
				}
				else if (ss[i]>='A'&&ss[i]<='Z')
				{
					printf("%c",ss[i]);
				}
			}
			if (ss[i]==' ')    
			{
				while(ss[i]==' ')      //此语句滤去所有空格
				{
					i++;
				}
				if (ss[i]>='a'&&ss[i]<='z') 
				{
					ss[i]-=32;
					printf("%c",ss[i]);
				}
				else if (ss[i]>='A'&&ss[i]<='Z')
				{
					printf("%c",ss[i]);
				}
				
			}
		}
		printf("\n");
	}
	return 0;
}


Compiler output:
a.cc: In function 'int main(int, char**)':
a.cc:16:17: error: 'gets' was not declared in this scope; did you mean 'getw'?
   16 |                 gets(ss);
      |                 ^~~~
      |                 getw
Language: C++

#include<iostream>

using namespace std;

int main()
{

string a, b, c;
cin >> a >> b >> c;

string e = a + b + c;

char d = e.at(7);

cout << "A" <<  d << "C" << endl;

Compiler output:
a.cc: In function 'int main()':
a.cc:15:34: error: expected '}' at end of input
   15 | cout << "A" <<  d << "C" << endl;
      |                                  ^
a.cc:6:1: note: to match this '{'
    6 | {
      | ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main(){
    string a,x,c;
    cin >> a >> x >> c;
    cout << A << x.at(0)  << C << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:13: error: 'A' was not declared in this scope
    7 |     cout << A << x.at(0)  << C << endl;
      |             ^
a.cc:7:30: error: 'C' was not declared in this scope
    7 |     cout << A << x.at(0)  << C << endl;
      |                              ^
Language: C++

#include <iostream>
#include <string>
using namespace std;
int main() {
  string a, b, c;
  cin >> a >> b >> c;
  cout << "A" + b[0] + "C" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:22: error: invalid operands of types 'const char*' and 'const char [2]' to binary 'operator+'
    7 |   cout << "A" + b[0] + "C" << endl;
      |                      ^ ~~~
      |                        |
      |                        const char [2]
Language: C++

#include <iostream>
#include <string>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  cout << "A" + b[0] + "C" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:18: error: invalid types 'int[int]' for array subscript
    7 |   cout << "A" + b[0] + "C" << endl;
      |                  ^
Language: C++

#include <iostream>
#include <string>
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  cout << "A" + b[0] + "C" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin >> a >> b >> c;
      |   ^~~
      |   std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:6:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |   cout << "A" + b[0] + "C" << endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:6:18: error: invalid types 'int[int]' for array subscript
    6 |   cout << "A" + b[0] + "C" << endl;
      |                  ^
a.cc:6:31: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    6 |   cout << "A" + b[0] + "C" << endl;
      |                               ^~~~
      |                               std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main () {
  string s;
  cin >> s;
  cout << "A" + s.at(8) + "C" << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:6:25: error: invalid operands of types 'const char*' and 'const char [2]' to binary 'operator+'
    6 |   cout << "A" + s.at(8) + "C" << endl;
      |           ~~~~~~~~~~~~~ ^ ~~~
      |               |           |
      |               const char* const char [2]
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  string A,B,C;
  cin >> A >> B >> C;
  cout << ‘A’<<B.at(0)<<‘C’<< endl;
}

Compiler output:
a.cc:7:11: error: extended character ‘ is not valid in an identifier
    7 |   cout << ‘A’<<B.at(0)<<‘C’<< endl;
      |           ^
a.cc:7:11: error: extended character ’ is not valid in an identifier
a.cc:7:25: error: extended character ‘ is not valid in an identifier
    7 |   cout << ‘A’<<B.at(0)<<‘C’<< endl;
      |                         ^
a.cc:7:25: error: extended character ’ is not valid in an identifier
a.cc: In function 'int main()':
a.cc:7:11: error: '\U00002018A\U00002019' was not declared in this scope
    7 |   cout << ‘A’<<B.at(0)<<‘C’<< endl;
      |           ^~~
a.cc:7:25: error: '\U00002018C\U00002019' was not declared in this scope
    7 |   cout << ‘A’<<B.at(0)<<‘C’<< endl;
      |                         ^~~
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  string A,B,C;
  cin >> A >> B >> C;
  cout << “A”<<B.at(0)<<“C”<< endl;
}

Compiler output:
a.cc:7:11: error: extended character “ is not valid in an identifier
    7 |   cout << “A”<<B.at(0)<<“C”<< endl;
      |           ^
a.cc:7:11: error: extended character ” is not valid in an identifier
a.cc:7:25: error: extended character “ is not valid in an identifier
    7 |   cout << “A”<<B.at(0)<<“C”<< endl;
      |                         ^
a.cc:7:25: error: extended character ” is not valid in an identifier
a.cc: In function 'int main()':
a.cc:7:11: error: '\U0000201cA\U0000201d' was not declared in this scope
    7 |   cout << “A”<<B.at(0)<<“C”<< endl;
      |           ^~~
a.cc:7:25: error: '\U0000201cC\U0000201d' was not declared in this scope
    7 |   cout << “A”<<B.at(0)<<“C”<< endl;
      |                         ^~~
Language: C++

#include "bits/stdc++.h"
using namespace std;

int main(void) {
    string a, b, c;
    cin >> a >> b >> c;

    cout << A << b.at(0) << C << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:13: error: 'A' was not declared in this scope
    8 |     cout << A << b.at(0) << C << endl;
      |             ^
a.cc:8:29: error: 'C' was not declared in this scope
    8 |     cout << A << b.at(0) << C << endl;
      |                             ^
Language: C++

#include "bits/stdc++.h"
using namespace std;

int main(void) {
    string s;
    cin >> s;

    cout << A << s.at(0) << C << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:13: error: 'A' was not declared in this scope
    8 |     cout << A << s.at(0) << C << endl;
      |             ^
a.cc:8:29: error: 'C' was not declared in this scope
    8 |     cout << A << s.at(0) << C << endl;
      |                             ^
Language: C++

#include<iostream>
#include<algorithm>
#include<string>
#include<functional>
#include<utility>
#include<stack>
#include<queue>
#include<cmath>
#include<list>
#include<cstdint>
#include<vector>
#include<map>
#include<deque>
#define rep(i,rept)	for(ll i = 0; i<rept;i++)
typedef long long ll;
const ll MOD = 1e9 + 7;
using namespace std;

int main() {
	//七日目

	cin.tie(0); ios::sync_with_stdio(false);

	string a, b, c;
	cin >> a >> b >> c;
	cout << 'A' << b[0] << 'C' << endl;
	
	return 0;
}#include<iostream>
#include<algorithm>
#include<string>
#include<functional>
#include<utility>
#include<stack>
#include<queue>
#include<cmath>
#include<list>
#include<cstdint>
#include<vector>
#include<map>
#include<deque>
#define rep(i,rept)	for(ll i = 0; i<rept;i++)
typedef long long ll;
const ll MOD = 1e9 + 7;
using namespace std;

int main() {
	//七日目

	cin.tie(0); ios::sync_with_stdio(false);

	string a, b, c;
	cin >> a >> b >> c;
	cout << 'A' << b[0] << 'C' << endl;
	
	return 0;
}

Compiler output:
a.cc:29:2: error: stray '#' in program
   29 | }#include<iostream>
      |  ^
a.cc:29:3: error: 'include' does not name a type
   29 | }#include<iostream>
      |   ^~~~~~~
a.cc:44:10: error: redefinition of 'const ll MOD'
   44 | const ll MOD = 1e9 + 7;
      |          ^~~
a.cc:16:10: note: 'const ll MOD' previously defined here
   16 | const ll MOD = 1e9 + 7;
      |          ^~~
a.cc:47:5: error: redefinition of 'int main()'
   47 | int main() {
      |     ^~~~
a.cc:19:5: note: 'int main()' previously defined here
   19 | int main() {
      |     ^~~~
Language: C++

#include <iostream>
#include <string>
using namespace std;
int main(){
string a,b,c;
cin>> a >> b >> c;
cout<<“A” << b.begin()<< “C” <<endl;
return 0;
}

Compiler output:
a.cc:7:7: error: extended character “ is not valid in an identifier
    7 | cout<<“A” << b.begin()<< “C” <<endl;
      |       ^
a.cc:7:7: error: extended character ” is not valid in an identifier
a.cc:7:26: error: extended character “ is not valid in an identifier
    7 | cout<<“A” << b.begin()<< “C” <<endl;
      |                          ^
a.cc:7:26: error: extended character ” is not valid in an identifier
a.cc: In function 'int main()':
a.cc:7:7: error: '\U0000201cA\U0000201d' was not declared in this scope
    7 | cout<<“A” << b.begin()<< “C” <<endl;
      |       ^~~
a.cc:7:26: error: '\U0000201cC\U0000201d' was not declared in this scope
    7 | cout<<“A” << b.begin()<< “C” <<endl;
      |                          ^~~
Language: C++

#include <iostream>
#include <string>
using namespace std;
int main(){
string a,b,c;
cin>> a >> b >> c;
cout<<“A” << b[0] << “C” <<endl;
return 0;
}

Compiler output:
a.cc:7:7: error: extended character “ is not valid in an identifier
    7 | cout<<“A” << b[0] << “C” <<endl;
      |       ^
a.cc:7:7: error: extended character ” is not valid in an identifier
a.cc:7:22: error: extended character “ is not valid in an identifier
    7 | cout<<“A” << b[0] << “C” <<endl;
      |                      ^
a.cc:7:22: error: extended character ” is not valid in an identifier
a.cc: In function 'int main()':
a.cc:7:7: error: '\U0000201cA\U0000201d' was not declared in this scope
    7 | cout<<“A” << b[0] << “C” <<endl;
      |       ^~~
a.cc:7:22: error: '\U0000201cC\U0000201d' was not declared in this scope
    7 | cout<<“A” << b[0] << “C” <<endl;
      |                      ^~~
Language: C

#include<stdio.h>

int main(){
  s[3][110];
  for(int i=0;i<3;i++)
    scanf("%s",s[i]);
  printf("A%cC\n",s[1][0]);
}

Compiler output:
main.c: In function 'main':
main.c:4:3: error: 's' undeclared (first use in this function)
    4 |   s[3][110];
      |   ^
main.c:4:3: note: each undeclared identifier is reported only once for each function it appears in
Language: C++

#include<iostream>
#include<string>
#include<stdio.h>
using namespace std;
int main(){
	char a[102];
	gets(a);
	for(int i=0;i<102;i++){
		if(a[i]==' '){
			cout<<"A"<<a[i+1]<<"C";
			return 0;
		}
	}
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:9: error: 'gets' was not declared in this scope; did you mean 'getw'?
    7 |         gets(a);
      |         ^~~~
      |         getw
Language: C++

#include<bits/stdc++.h>
using namespace std;
string a,b,c;
int main(){
    cin>>a>>b>>c;/
    cout<<a[0]<<b[0]<<c[0]<<endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:18: error: expected primary-expression before '/' token
    5 |     cin>>a>>b>>c;/
      |                  ^
Language: C++

#include<bits/c++.h>
using namespace std;
string a,b,c;
int main()
    {
        cin>>a>>b>>c;
        cout<<a[0]<<b[0]<<c[0]<<endl;
        return 0;
    }

Compiler output:
a.cc:1:9: fatal error: bits/c++.h: No such file or directory
    1 | #include<bits/c++.h>
      |         ^~~~~~~~~~~~
compilation terminated.
Language: C++

#include <cstring>
#include <iostream>
int main()
{
    char a[10000];
    for(int i=1;i<=3;i++)
    {
        cin>>a;
        cout<<a[0];
    }
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    8 |         cin>>a;
      |         ^~~
      |         std::cin
In file included from a.cc:2:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:9:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |         cout<<a[0];
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main()
{string a,b,c
cin>>a>>b>>c;
cout<<a[0]<<b[0]<<c[0]<<endl;
return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:1: error: expected initializer before 'cin'
    5 | cin>>a>>b>>c;
      | ^~~
a.cc:6:19: error: 'c' was not declared in this scope
    6 | cout<<a[0]<<b[0]<<c[0]<<endl;
      |                   ^
Language: C++

#include<iostream>
using namespace std;
int main(){
 string a,s,c;
 cin>>a>>s>>c;
 x=s.at(0);
 cout<<a[0]<<s[0]<<c[0]<<endl;
 return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:2: error: 'x' was not declared in this scope
    6 |  x=s.at(0);
      |  ^
Language: C++

#include<bits/stdc++.h>
using namespace std;
int main()
{
    char a[101],b[101],c[101];
    cin>>a>>b>>c;
    cout<<a[0]<<<<b[0]<<<<c[0];
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:17: error: expected primary-expression before '<<' token
    7 |     cout<<a[0]<<<<b[0]<<<<c[0];
      |                 ^~
a.cc:7:25: error: expected primary-expression before '<<' token
    7 |     cout<<a[0]<<<<b[0]<<<<c[0];
      |                         ^~
Language: C++

#include<bits/stdc++.h>
using namespace std;
string a,b,c;
int main()
{
    cin>>a>>b>>c;
    cout<<a[0]<<b[0]<<[0];
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:24: error: expected identifier before numeric constant
    7 |     cout<<a[0]<<b[0]<<[0];
      |                        ^
a.cc: In lambda function:
a.cc:7:26: error: expected '{' before ';' token
    7 |     cout<<a[0]<<b[0]<<[0];
      |                          ^
Language: C++

#include<bits/stdc++.h>
#include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
string a,b,c;
int main()
{
    cin>>a>>b>>c;
    cout<<a[0]<<b[0]<<[0];
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:10:24: error: expected identifier before numeric constant
   10 |     cout<<a[0]<<b[0]<<[0];
      |                        ^
a.cc: In lambda function:
a.cc:10:26: error: expected '{' before ';' token
   10 |     cout<<a[0]<<b[0]<<[0];
      |                          ^
Language: C++

#include<bits/stdc++.h>//万能头
using namespace std;
int main()//主程序
{
    string a;//string
	string b;//string
	string c;//string
	int x,y,z;//int
	getline(cin,a);//输入 
	getline(cin,b);//输入 
	getline(cin,c);//输入 
	x=a.size();//取一个长度 
	for(int i=0;i<n;i++)//循环 
	{
		cout<<a[i]<<b[i]<<c[i]<<endl;//截取第一个数字输出 
	} 
	return 0;//返回 
}


Compiler output:
a.cc: In function 'int main()':
a.cc:13:23: error: 'n' was not declared in this scope
   13 |         for(int i=0;i<n;i++)//循环
      |                       ^
Language: C++

#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
int main(){
	char a;
	cin>>a;
	cout<<"A"<<a[0]<<"C"<<endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:9:21: error: invalid types 'char[int]' for array subscript
    9 |         cout<<"A"<<a[0]<<"C"<<endl;
      |                     ^
Language: C++

#include <stdio.h>
int main (){
char a[118];
for(int i=0;i<118;i++){
scanf('%1c',&a[i]);
}
printf("A'%1c'C",a[8]);

return 0;
}

Compiler output:
a.cc:5:7: warning: multi-character character constant [-Wmultichar]
    5 | scanf('%1c',&a[i]);
      |       ^~~~~
a.cc: In function 'int main()':
a.cc:5:7: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
    5 | scanf('%1c',&a[i]);
      |       ^~~~~
      |       |
      |       int
In file included from a.cc:1:
/usr/include/stdio.h:428:42: note:   initializing argument 1 of 'int scanf(const char*, ...)'
  428 | extern int scanf (const char *__restrict __format, ...) __wur;
      |                   ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
Language: C++

#include <stdio.h>
int main (){
char a[118];
for(int i=0;i<118;i++){
scanf('%c',&a[i]);
}
printf("A'%c'C",a[8]);

return 0;
}

Compiler output:
a.cc:5:7: warning: multi-character character constant [-Wmultichar]
    5 | scanf('%c',&a[i]);
      |       ^~~~
a.cc: In function 'int main()':
a.cc:5:7: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
    5 | scanf('%c',&a[i]);
      |       ^~~~
      |       |
      |       int
In file included from a.cc:1:
/usr/include/stdio.h:428:42: note:   initializing argument 1 of 'int scanf(const char*, ...)'
  428 | extern int scanf (const char *__restrict __format, ...) __wur;
      |                   ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
Language: C++

#include<iostream>
#include<cstring>
string a,b,c;
int main(){
    cin>>a>>b>>c;
    cout<<a[0]<<b[0]<<c[0]<<endl;
    return 0;
}

Compiler output:
a.cc:3:1: error: 'string' does not name a type; did you mean 'stdin'?
    3 | string a,b,c;
      | ^~~~~~
      | stdin
a.cc: In function 'int main()':
a.cc:5:5: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |     cin>>a>>b>>c;
      |     ^~~
      |     std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:5:10: error: 'a' was not declared in this scope
    5 |     cin>>a>>b>>c;
      |          ^
a.cc:5:13: error: 'b' was not declared in this scope
    5 |     cin>>a>>b>>c;
      |             ^
a.cc:5:16: error: 'c' was not declared in this scope
    5 |     cin>>a>>b>>c;
      |                ^
a.cc:6:5: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |     cout<<a[0]<<b[0]<<c[0]<<endl;
      |     ^~~~
      |     std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:6:29: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    6 |     cout<<a[0]<<b[0]<<c[0]<<endl;
      |                             ^~~~
      |                             std::endl
In file included from /usr/include/c++/14/iostream:41:
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

#include<iostream>
#include<cstring>
int main(){
    string s;
    std::cin>>s;std::cout<<s[0];
    std::cin>>s;std::cout<<s[0];
    std::cin>>s;std::cout<<s[0]<<"\n";
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:5: error: 'string' was not declared in this scope
    4 |     string s;
      |     ^~~~~~
a.cc:4:5: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:5:15: error: 's' was not declared in this scope
    5 |     std::cin>>s;std::cout<<s[0];
      |               ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main()
{
	string a,b,c;
	cin>>a>>b>>c;
	cout<<a[0]<<" "<<b[0]<<" "<<c[0]endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:41: error: expected ';' before 'endl'
    7 |         cout<<a[0]<<" "<<b[0]<<" "<<c[0]endl;
      |                                         ^~~~
      |                                         ;
Language: C++

#include <bits/stdc++.h>
using namespace std;
int main()
{
	string a,b,c;
	cin>>a>>b>>c;
	cout<<a[0]<<" "<<b[0]<<" "<<<<c[0]endl;
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:7:37: error: expected primary-expression before '<<' token
    7 |         cout<<a[0]<<" "<<b[0]<<" "<<<<c[0]endl;
      |                                     ^~
Language: C++

#include<iostrema>
#include<cstring>
using namespace std;
int main()
{
	string a,b,c;
	cin>>a>>b>>c;
	cout<<a[0]<<b[0]<<c[0];
	return 0;
}

Compiler output:
a.cc:1:9: fatal error: iostrema: No such file or directory
    1 | #include<iostrema>
      |         ^~~~~~~~~~
compilation terminated.
Language: C++

#include <iostream>
#include <cstdio>
#include <cstring>
string a,b,c;
int main()
{
	cin.sync_with_stdio(false);
	cin>>a>>b>>c;
	cout<<a[0]<<b[0]<<c[0];
	return 0;
}

Compiler output:
a.cc:4:1: error: 'string' does not name a type; did you mean 'stdin'?
    4 | string a,b,c;
      | ^~~~~~
      | stdin
a.cc: In function 'int main()':
a.cc:7:9: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    7 |         cin.sync_with_stdio(false);
      |         ^~~
      |         std::cin
In file included from a.cc:1:
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:8:14: error: 'a' was not declared in this scope
    8 |         cin>>a>>b>>c;
      |              ^
a.cc:8:17: error: 'b' was not declared in this scope
    8 |         cin>>a>>b>>c;
      |                 ^
a.cc:8:20: error: 'c' was not declared in this scope
    8 |         cin>>a>>b>>c;
      |                    ^
a.cc:9:9: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    9 |         cout<<a[0]<<b[0]<<c[0];
      |         ^~~~
      |         std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main(void){
  string s;

  cin >> s;

  cout << A << s.front() << C << endl;

  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:11: error: 'A' was not declared in this scope
    9 |   cout << A << s.front() << C << endl;
      |           ^
a.cc:9:29: error: 'C' was not declared in this scope
    9 |   cout << A << s.front() << C << endl;
      |                             ^
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  string s;
  cin >> AtCoder >> s >> Contest;
  cout << "AtCoder" << s.at(0) << "Contest" << endl;
  
}


Compiler output:
a.cc: In function 'int main()':
a.cc:6:10: error: 'AtCoder' was not declared in this scope
    6 |   cin >> AtCoder >> s >> Contest;
      |          ^~~~~~~
a.cc:6:26: error: 'Contest' was not declared in this scope; did you mean 'const'?
    6 |   cin >> AtCoder >> s >> Contest;
      |                          ^~~~~~~
      |                          const
Language: C

#include <stdio.h>
#include <string>
int main(){
char At[100];
char s[110];
char Co[120];
scanf("%s%s%s",&At,&s,&Co );
printf("%c%c%c\n",At[0],s[0],Co[0] );
return 0;





}


Compiler output:
main.c:2:10: fatal error: string: No such file or directory
    2 | #include <string>
      |          ^~~~~~~~
compilation terminated.
Language: C

include<stdio.h>
int main(){
  char s;
  scanf("AtCoder %c",&s);
  printf("A%cC",s);
  return 0;
}

Compiler output:
main.c:1:8: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
    1 | include<stdio.h>
      |        ^
Language: C

#include <stdio.h>
#include <string>
int main(){
char At[100];
char s[110]
char Co[120]
scanf("%s%s%s",&At,&s,&Co );
printf("%c%c%c\n",At[0],s[0],Co[0] );
return 0;





}


Compiler output:
main.c:2:10: fatal error: string: No such file or directory
    2 | #include <string>
      |          ^~~~~~~~
compilation terminated.
Language: C++

include <bits/stdc++.h>
using namespace std;
int main() {
  string a, b, c;
  cin >> a >> b >> c;
  cout << 'A' << b[0] << 'C' << endl;
}

Compiler output:
a.cc:1:1: error: 'include' does not name a type
    1 | include <bits/stdc++.h>
      | ^~~~~~~
a.cc: In function 'int main()':
a.cc:4:3: error: 'string' was not declared in this scope
    4 |   string a, b, c;
      |   ^~~~~~
a.cc:5:3: error: 'cin' was not declared in this scope
    5 |   cin >> a >> b >> c;
      |   ^~~
a.cc:5:10: error: 'a' was not declared in this scope
    5 |   cin >> a >> b >> c;
      |          ^
a.cc:5:15: error: 'b' was not declared in this scope
    5 |   cin >> a >> b >> c;
      |               ^
a.cc:5:20: error: 'c' was not declared in this scope
    5 |   cin >> a >> b >> c;
      |                    ^
a.cc:6:3: error: 'cout' was not declared in this scope
    6 |   cout << 'A' << b[0] << 'C' << endl;
      |   ^~~~
a.cc:6:33: error: 'endl' was not declared in this scope
    6 |   cout << 'A' << b[0] << 'C' << endl;
      |                                 ^~~~
Language: C++

#include <bits/stdc++.h>
#include <typeinfo>
#include <cxxabi.h>
#ifdef LOCAL
  #include "dbgtoki.hpp"
  #define DUMP(i) dump((string)TOSTRING(i), demangle(typeid(i).name()), __LINE__ , i) 
DbgTimer D_t;
  #define TSTART() D_t.start()
  #define TSTOP() D_t.stop()
#else
  #define DUMP(i) 
  #define TSTART()
  #define TSTOP()  
#endif
 
#define TOSTRING(x) #x
#define SZ(x) (int)(x).size()
#define REP(i,n) for(int i=0;i<(n);i++)
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define ALL(s) (s).begin(), (s).end()
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()) , v.end());
using namespace std;
typedef long long unsigned int llu;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;

const int EPS = 1e-9;



int main (){
  cin.tie(0);
  ios::sync_with_stdio(false);
  string a,s,c;
  while(cin >> a >> s >> c){
    TSTART();
    string ans = "A" + s[0] + "C";    
    cout << ans << endl;
    TSTOP();
  }
    return 0;
}



Compiler output:
a.cc: In function 'int main()':
a.cc:38:29: error: invalid operands of types 'const char*' and 'const char [2]' to binary 'operator+'
   38 |     string ans = "A" + s[0] + "C";
      |                             ^ ~~~
      |                               |
      |                               const char [2]
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  string A=AtCoder;
  string B;
  string C=Contest;
  cin >> B;
  cout << A.at(0) << B.at(0) << C.at(0) << endl;
  

  

}


Compiler output:
a.cc: In function 'int main()':
a.cc:5:12: error: 'AtCoder' was not declared in this scope
    5 |   string A=AtCoder;
      |            ^~~~~~~
a.cc:7:12: error: 'Contest' was not declared in this scope; did you mean 'const'?
    7 |   string C=Contest;
      |            ^~~~~~~
      |            const
Language: C++

#include <cstdio>
using namespace std;
int main(void){
  char b[1000];
  gets(b);
  printf("A%cC\n",b[8]);
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'gets' was not declared in this scope; did you mean 'getw'?
    5 |   gets(b);
      |   ^~~~
      |   getw
Language: C++

#include <iostream>
#include<cstring>
#include<string>
#include<bits/c++.h>
using namespace std;
char miku[105];

int main()
{
    gets(miku); 
    int rin=strlen(miku);
    cout<<miku[0]; 
    for(int i=1; i<rin; i++)
        if(miku[i]==' ')   
            cout<<miku[i+1];
    cout<<endl;
    return 0;
}


Compiler output:
a.cc:4:9: fatal error: bits/c++.h: No such file or directory
    4 | #include<bits/c++.h>
      |         ^~~~~~~~~~~~
compilation terminated.
Language: C++

#include <iostream>
#include<cstring>
#include<string>
using namespace std;
char miku[105];

int main()
{
    gets(miku); 
    int rin=strlen(miku);
    cout<<miku[0]; 
    for(int i=1; i<rin; i++)
        if(miku[i]==' ')   
            cout<<miku[i+1];
    cout<<endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:9:5: error: 'gets' was not declared in this scope; did you mean 'getw'?
    9 |     gets(miku);
      |     ^~~~
      |     getw
Language: C++

#include <iostream>
#include<cstring>
using namespace std;
char miku[105];

int main()
{
    gets(miku); 
    int rin=strlen(miku);
    cout<<miku[0]; 
    for(int i=1; i<rin; i++)
        if(miku[i]==' ')   
            cout<<miku[i+1];
    cout<<endl;
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:8:5: error: 'gets' was not declared in this scope; did you mean 'getw'?
    8 |     gets(miku);
      |     ^~~~
      |     getw
Language: C++

#include <iostream>
#inlcude <string>
using namespace std;

int main() {
  string A, B, C; cin >> A >> B >> C;
  cout << A[0] << B[0] << C[0] << endl;
  return 0;
}

Compiler output:
a.cc:2:2: error: invalid preprocessing directive #inlcude; did you mean #include?
    2 | #inlcude <string>
      |  ^~~~~~~
      |  include
Language: C++

#include<iostream>
#include<string>
using namespace std;
char a[10];
char c[10];
char b[10];
int main()
{	
    gets(a);
    gets(b);
    gets(c);
	cout<<a[0]<<b[0]<<c[0];
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
	
    
    
    
    




	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:9:5: error: 'gets' was not declared in this scope; did you mean 'getw'?
    9 |     gets(a);
      |     ^~~~
      |     getw
Language: C++

#include <iostream>
using namespace std;
int main(void){
    // Your code here!
    string a, b;
    cin a >> b ;
    cout << "A" << b.at(0) << "C" << endl;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:6:8: error: expected ';' before 'a'
    6 |     cin a >> b ;
      |        ^~
      |        ;
Language: C++

#include <bits/stdc++.h>
using namespace std;

int main() {
  String s[3];
  cin >> s[0] >> s[1] >> s[2];
  cout << "A" << s[1].at(0) << "C";
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:3: error: 'String' was not declared in this scope
    5 |   String s[3];
      |   ^~~~~~
a.cc:6:10: error: 's' was not declared in this scope
    6 |   cin >> s[0] >> s[1] >> s[2];
      |          ^
Language: C++

#include <bits/stdc++.h>
using namespace std;
 
int main() {
	string A, B, C;
	cin >> A >> B >> C
	char s = B.at(0);
	cout << 'A' + s + 'C' << endl;
	}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:27: error: expected ';' before 'char'
    6 |         cin >> A >> B >> C
      |                           ^
      |                           ;
    7 |         char s = B.at(0);
      |         ~~~~               
a.cc:8:23: error: 's' was not declared in this scope
    8 |         cout << 'A' + s + 'C' << endl;
      |                       ^
Language: C++

#include<iostream>
using namespace std;

int main(){
  
  string s1,s2,s3;

  cin >> s1 >> s2 >> s3;

  cout << "A" + s2[0] + "C" << endl;
  
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:23: error: invalid operands of types 'const char*' and 'const char [2]' to binary 'operator+'
   10 |   cout << "A" + s2[0] + "C" << endl;
      |                       ^ ~~~
      |                         |
      |                         const char [2]
Language: C++

#include<iostream>
#include<string.h>
int main(){
  string s;
  cin>>s;
  char ans=s[8];
  cout<<"A"<<ans<<"C"<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:3: error: 'string' was not declared in this scope
    4 |   string s;
      |   ^~~~~~
a.cc:4:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin>>s;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:5:8: error: 's' was not declared in this scope
    5 |   cin>>s;
      |        ^
a.cc:7:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    7 |   cout<<"A"<<ans<<"C"<<endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:7:24: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    7 |   cout<<"A"<<ans<<"C"<<endl;
      |                        ^~~~
      |                        std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

#include<iostream>
#include<string.h>
int main(){
  string s="";
  cin>>s;
  char ans=s[8];
  cout<<"A"<<ans<<"C"<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:3: error: 'string' was not declared in this scope
    4 |   string s="";
      |   ^~~~~~
a.cc:4:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin>>s;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:5:8: error: 's' was not declared in this scope
    5 |   cin>>s;
      |        ^
a.cc:7:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    7 |   cout<<"A"<<ans<<"C"<<endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:7:24: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    7 |   cout<<"A"<<ans<<"C"<<endl;
      |                        ^~~~
      |                        std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: Java

import java.util.Scanner;
public class Main048{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String name = sc.nextLine();
        System.out.println(name);
        System.out.println("A" + name.charAt(8) + "C");
    }
}


Compiler output:
Main.java:2: error: class Main048 is public, should be declared in a file named Main048.java
public class Main048{
       ^
1 error
Language: C++

#include <iostream>
#include <string>
int main(){
  string a;
  cin>>a;
  cout<<'A'<<a[8]<<'C'<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:3: error: 'string' was not declared in this scope
    4 |   string a;
      |   ^~~~~~
a.cc:4:3: note: suggested alternatives:
In file included from /usr/include/c++/14/iosfwd:41,
                 from /usr/include/c++/14/ios:40,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stringfwd.h:77:33: note:   'std::string'
   77 |   typedef basic_string<char>    string;
      |                                 ^~~~~~
In file included from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44:
/usr/include/c++/14/string:76:11: note:   'std::pmr::string'
   76 |     using string    = basic_string<char>;
      |           ^~~~~~
a.cc:5:3: error: 'cin' was not declared in this scope; did you mean 'std::cin'?
    5 |   cin>>a;
      |   ^~~
      |   std::cin
/usr/include/c++/14/iostream:62:18: note: 'std::cin' declared here
   62 |   extern istream cin;           ///< Linked to standard input
      |                  ^~~
a.cc:5:8: error: 'a' was not declared in this scope
    5 |   cin>>a;
      |        ^
a.cc:6:3: error: 'cout' was not declared in this scope; did you mean 'std::cout'?
    6 |   cout<<'A'<<a[8]<<'C'<<endl;
      |   ^~~~
      |   std::cout
/usr/include/c++/14/iostream:63:18: note: 'std::cout' declared here
   63 |   extern ostream cout;          ///< Linked to standard output
      |                  ^~~~
a.cc:6:25: error: 'endl' was not declared in this scope; did you mean 'std::endl'?
    6 |   cout<<'A'<<a[8]<<'C'<<endl;
      |                         ^~~~
      |                         std::endl
/usr/include/c++/14/ostream:744:5: note: 'std::endl' declared here
  744 |     endl(basic_ostream<_CharT, _Traits>& __os)
      |     ^~~~
Language: C++

#include <bits/stdc++.h>
#define rep(i,n) for(int i=1;i<=n;++i)
#define YES cout<<"YES"<<endl
#define NO cout<<"NO"<<endl
using namespace std;

int main(){
  int a,b,c;
  cout << a << b << c;
  cout << "A" << b.at(0) << "C" << endl;
  return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:10:20: error: request for member 'at' in 'b', which is of non-class type 'int'
   10 |   cout << "A" << b.at(0) << "C" << endl;
      |                    ^~
Language: C

#include<stdio.h>
int main(void)
{
char str1[100],str2[100],str3[100];
  scanf("%s %s %s",str1,str2,str3);
  printf("%c%c%c\n",str1[0],str2[0],str3[0]);
  return 0
}

  

Compiler output:
main.c: In function 'main':
main.c:7:11: error: expected ';' before '}' token
    7 |   return 0
      |           ^
      |           ;
    8 | }
      | ~
Language: C++

#include <iostream>
using namespace std;

int main(){
	char s[100];
	cout << "AtCoder" << endl;
	cin >> s;
	cou << "Contest" << endl;
	cout << "A" << s[0] << "C";
}

Compiler output:
a.cc: In function 'int main()':
a.cc:8:9: error: 'cou' was not declared in this scope
    8 |         cou << "Contest" << endl;
      |         ^~~
Language: Java

public static void main(String[] args) {

		if (args[0].equals("AtCoder") && args[2].equals(" Contest ")
				&& args[1].length() > 0 && args[1].length() < 100) {
			for (int i = 0; i < args.length; i++) {
				System.out.print(args[i].substring(0, 1));
			}
 		}

	}

Compiler output:
Main.java:1: error: unnamed classes are a preview feature and are disabled by default.
public static void main(String[] args) {
              ^
  (use --enable-preview to enable unnamed classes)
1 error
Language: Java

public static void main(String[] args) {

		for (int i = 0; i < args.length; i++) {
			System.out.print(args[i].substring(0, 1));
		}

	}

Compiler output:
Main.java:1: error: unnamed classes are a preview feature and are disabled by default.
public static void main(String[] args) {
              ^
  (use --enable-preview to enable unnamed classes)
1 error
Language: Java

for (int i = 0; i < args.length; i++) {
			System.out.print(args[i].substring(0, 1));
		}

Compiler output:
Main.java:1: error: class, interface, enum, or record expected
for (int i = 0; i < args.length; i++) {
^
Main.java:1: error: class, interface, enum, or record expected
for (int i = 0; i < args.length; i++) {
                ^
Main.java:1: error: class, interface, enum, or record expected
for (int i = 0; i < args.length; i++) {
                                 ^
Main.java:3: error: class, interface, enum, or record expected
		}
		^
4 errors
Language: Java

package virtualContest;

public class A {

	public static void main(String[] args) {

		for (int i = 0; i < args.length; i++) {
			System.out.print(args[i].substring(0, 1));
		}

	}

}


Compiler output:
Main.java:3: error: class A is public, should be declared in a file named A.java
public class A {
       ^
1 error
Language: Java

public class Hoge {
	public static void main(String[] args) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		System.out.println(shorten(in.readLine()));

	}

	static String shorten(String src) {
		return src.replaceAll("([A-Z])[a-z]* ([A-Z])[a-z]* ([A-Z])[a-z]*", "$1$2$3");
	}
}

Compiler output:
Main.java:1: error: class Hoge is public, should be declared in a file named Hoge.java
public class Hoge {
       ^
Main.java:2: error: cannot find symbol
	public static void main(String[] args) throws IOException {
	                                              ^
  symbol:   class IOException
  location: class Hoge
Main.java:3: error: cannot find symbol
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		^
  symbol:   class BufferedReader
  location: class Hoge
Main.java:3: error: cannot find symbol
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		                        ^
  symbol:   class BufferedReader
  location: class Hoge
Main.java:3: error: cannot find symbol
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		                                           ^
  symbol:   class InputStreamReader
  location: class Hoge
5 errors
Language: C++

#include <stdio.h>
int main(){
	char a,b,c,d;
	scanf("%s %s %s",&a,&b,&c);
	d=b[0];
	printf("A%sC",d);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:12: error: invalid types 'char[int]' for array subscript
    5 |         d=b[0];
      |            ^
Language: C++

#include <stdio.h>
int main(){
	char a,b,c;
	scanf("%s %s %s",&a,&b,&c);
	printf("A%sC",b[0]);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:5:24: error: invalid types 'char[int]' for array subscript
    5 |         printf("A%sC",b[0]);
      |                        ^
Language: C++

#include <stdio.h>
int main(){
	char a,b,c;
	scanf("%s %s %s",&a,%b,%c);
	printf("%s %s %s",a[0],b[0],c[0]);
	return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:4:29: error: expected primary-expression before '%' token
    4 |         scanf("%s %s %s",&a,%b,%c);
      |                             ^
a.cc:4:32: error: expected primary-expression before '%' token
    4 |         scanf("%s %s %s",&a,%b,%c);
      |                                ^
a.cc:5:28: error: invalid types 'char[int]' for array subscript
    5 |         printf("%s %s %s",a[0],b[0],c[0]);
      |                            ^
a.cc:5:33: error: invalid types 'char[int]' for array subscript
    5 |         printf("%s %s %s",a[0],b[0],c[0]);
      |                                 ^
a.cc:5:38: error: invalid types 'char[int]' for array subscript
    5 |         printf("%s %s %s",a[0],b[0],c[0]);
      |                                      ^
Language: C++

#include <iostream>
#include <string>
int main(){
std::string a,b,c;
std::cin >> a >> b >>c;
std::cout << 'A' << S[0] << 'C' << std::endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:6:21: error: 'S' was not declared in this scope
    6 | std::cout << 'A' << S[0] << 'C' << std::endl;
      |                     ^