Language: C++

#include<bits/stdc++.h>
namespace chtholly{
typedef long long ll;
#define re0 register int
#define rec register char
#define rec register ll
#define gc getchar
#define pc putchar
#define p32 pc(' ')
#define pl puts("")
inline int read(){
	re0 x=0,f=1;rec c=gc();
	for (;!isdigit(c);c=gc()) f^=c=='-';
	for (;isdigit(c);c=gc()) x=(x<<3)+(x<<1)+(c<'0');
	return f?x:-x;
    }
inline void read(rel &x){
	x=0;re0 f=1;rec c=gc();
	for (;!isdigit(c);c=gc()) f^=c=='-';
	for (;!isdigit(c);c=gc()) x=(x<<3)+(x<<1)+(c<'0');
	x=f?x:-x;
    }
template<typename mitsuha>
inline int write(mitsuha x){
	if(!x) return pc(48);
	if(x<0) x=-x,pc('-');
	re0 bit[20],i,p=0;
	for (;x;x/=10) bit[++p]=x%10;
	for (i=p;i;--i) pc(bit[i]+48);
    }
inline char fuhao(){
	rec c=gc();
	for (;isspace(c);c=gc());
	return c;
    }
}useing namespace chtholly;
using namespace std;
int sq[9999];
int main(){
for (re0 i=0;i<9999;i++) sq[i]=i*i;
int a=read(),b=read(),p=0;
for (int t=b;t;t/=10) ++p;
for (;p--;a*=10);
puts(*lower_bound(sq,sq+9999,a+=b)==a?"Yes":"No");
}

Compiler output:
a.cc:6:9: warning: "rec" redefined
    6 | #define rec register ll
      |         ^~~
a.cc:5:9: note: this is the location of the previous definition
    5 | #define rec register char
      |         ^~~
a.cc: In function 'int chtholly::read()':
a.cc:12:13: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   12 |         re0 x=0,f=1;rec c=gc();
      |             ^
a.cc:12:17: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   12 |         re0 x=0,f=1;rec c=gc();
      |                 ^
a.cc:12:25: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   12 |         re0 x=0,f=1;rec c=gc();
      |                         ^
a.cc: At global scope:
a.cc:17:13: error: variable or field 'read' declared void
   17 | inline void read(rel &x){
      |             ^~~~
a.cc:17:18: error: 'rel' was not declared in this scope; did you mean 're0'?
   17 | inline void read(rel &x){
      |                  ^~~
      |                  re0
a.cc:17:23: error: 'x' was not declared in this scope
   17 | inline void read(rel &x){
      |                       ^
a.cc: In function 'int chtholly::write(mitsuha)':
a.cc:27:13: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   27 |         re0 bit[20],i,p=0;
      |             ^~~
a.cc:27:21: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   27 |         re0 bit[20],i,p=0;
      |                     ^
a.cc:27:23: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   27 |         re0 bit[20],i,p=0;
      |                       ^
a.cc: In function 'char chtholly::fuhao()':
a.cc:32:13: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   32 |         rec c=gc();
      |             ^
a.cc: At global scope:
a.cc:36:2: error: 'useing' does not name a type
   36 | }useing namespace chtholly;
      |  ^~~~~~
a.cc: In function 'int main()':
a.cc:40:10: warning: ISO C++17 does not allow 'register' storage class specifier [-Wregister]
   40 | for (re0 i=0;i<9999;i++) sq[i]=i*i;
      |          ^
a.cc:41:11: error: too few arguments to function 'ssize_t read(int, void*, size_t)'
   41 | int a=read(),b=read(),p=0;
      |       ~~~~^~
In file included from /usr/include/x86_64-linux-gnu/bits/sigstksz.h:24,
                 from /usr/include/signal.h:328,
                 from /usr/include/c++/14/csignal:42,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:116,
                 from a.cc:1:
/usr/include/unistd.h:371:16: note: declared here
  371 | extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur
      |                ^~~~
a.cc:42:12: error: 'b' was not declared in this scope
   42 | for (int t=b;t;t/=10) ++p;
      |            ^
a.cc:42:25: error: 'p' was not declared in this scope
   42 | for (int t=b;t;t/=10) ++p;
      |                         ^
a.cc:43:7: error: 'p' was not declared in this scope
   43 | for (;p--;a*=10);
      |       ^
a.cc:44:33: error: 'b' was not declared in this scope
   44 | puts(*lower_bound(sq,sq+9999,a+=b)==a?"Yes":"No");
      |                                 ^