Language: C++

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define debug(n) cout << "DEBUG1 " << n << "\n";
#define debug2(n, m) cout << "DEBUG2 " << n << ' ' << m << "\n";
#define debug3(n, m, x) cout << "DEBUG3 " << n << ' ' << m << ' ' << x << "\n";
#define ss_def stringstream ss // stringstream, do ss_def(str), then ss >> n (n is int)
#define upzero(n) if (n < 0) n = 0
using namespace std;
int main() {
	for (int i = 0;i <= 7;i++) {#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define debug(n) cout << "DEBUG1 " << n << "\n";
#define debug2(n, m) cout << "DEBUG2 " << n << ' ' << m << "\n";
#define debug3(n, m, x) cout << "DEBUG3 " << n << ' ' << m << ' ' << x << "\n";
#define ss_def stringstream ss // stringstream, do ss_def(str), then ss >> n (n is int)
#define upzero(n) if (n < 0) n = 0
#pragma GCC optimize("Ofast")
using namespace std;
ll int BtoPmodM(ll int b, ll int p, ll int m) { // (b ^ p) % m (Big Mod)
    b %= m;
    if (p == 0) return 1;
    else if (p % 2 == 0) return (BtoPmodM(b, p / 2, m) * BtoPmodM(b, p / 2, m)) % m; // a^(p/2) * a^(p/2) = a^p
    else if (p % 2 == 1) return (BtoPmodM(b, (p - 1) / 2, m) * BtoPmodM(b, (p - 1) / 2, m) * b) % m; // +1
    else return 0; // a function must return something
}
ll int euclid_algo(ll int a, ll int b) { // Euclidean Algorithm
    if (b == 0) return a;
    else return euclid_algo(b,a % b);
}
bool coprime(ll int a, ll int b) {
    if (euclid_algo(a, b) == 1) return true;
    else return false;
}
ll int factModP(ll int n, ll int p) {
    ll int fac[n - 1];
    fac[0] = 1;
    for (ll int i = 1;i <= n;i++) {
        fac[i] = fac[i - 1] * i % p;
    }
    return fac[n];
}
ll int power(ll int x, ll int y, ll int p) { // x ^ y % p
    ll int res = 1;
    x = x % p;
    while (y > 0) { 
        if (y & 1) res = (res * x) % p; 
        y /= 2; 
        x = (x * x) % p; 
    } 
    return res; 
}
ll int modInverse(ll int n, ll int p) {
    return power(n, p - 2, p); 
}
ll int nCrModP(ll int n, ll int r, ll int p) {
    if (r == 0) return 1;
    else if (r > n) return 0;
    ll int fac[n + 1]; 
    fac[0] = 1; 
    for (ll int i = 1;i <= n;i++) {
        fac[i] = fac[i - 1] * i % p; 
    }
    return (fac[n] * modInverse(fac[r], p) % p * modInverse(fac[n - r], p) % p) % p; 
}
ll int nCr(ll int n, ll int r) {
    ll int ans = 1;
     if (r >= n - r) {
         for (ll int i = r + 1;i <= n;i++) ans *= i;
         for (ll int i = 1;i <= n - r;i++) ans /= i;
     } else {
         for (ll int i = n - r + 1;i <= n;i++) ans *= i;
         for (ll int i = 1;i <= r;i++) ans /= i;
     }
     return ans;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    // implementation
    string str;
    cin >> str;
    int strl = str.length();
    for (int i = 0;i < strl;i++) {
    	if (str[i] == '7') {
    		cout << "Yes\n";
    		return 0;
		}
	}
	cout << "No\n";
}
}

Compiler output:
a.cc:11:37: error: stray '#' in program
   11 |         for (int i = 0;i <= 7;i++) {#include <bits/stdc++.h>
      |                                     ^
a.cc: In function 'int main()':
a.cc:11:38: error: 'include' was not declared in this scope
   11 |         for (int i = 0;i <= 7;i++) {#include <bits/stdc++.h>
      |                                      ^~~~~~~
a.cc:11:47: error: 'bits' was not declared in this scope
   11 |         for (int i = 0;i <= 7;i++) {#include <bits/stdc++.h>
      |                                               ^~~~
a.cc:11:52: error: 'stdc' was not declared in this scope; did you mean 'std'?
   11 |         for (int i = 0;i <= 7;i++) {#include <bits/stdc++.h>
      |                                                    ^~~~
      |                                                    std
a.cc:19:9: error: '#pragma' is not allowed here
   19 | #pragma GCC optimize("Ofast")
      |         ^~~
a.cc:21:47: error: a function-definition is not allowed here before '{' token
   21 | ll int BtoPmodM(ll int b, ll int p, ll int m) { // (b ^ p) % m (Big Mod)
      |                                               ^
a.cc:28:40: error: a function-definition is not allowed here before '{' token
   28 | ll int euclid_algo(ll int a, ll int b) { // Euclidean Algorithm
      |                                        ^
a.cc:32:34: error: a function-definition is not allowed here before '{' token
   32 | bool coprime(ll int a, ll int b) {
      |                                  ^
a.cc:36:37: error: a function-definition is not allowed here before '{' token
   36 | ll int factModP(ll int n, ll int p) {
      |                                     ^
a.cc:44:44: error: a function-definition is not allowed here before '{' token
   44 | ll int power(ll int x, ll int y, ll int p) { // x ^ y % p
      |                                            ^
a.cc:54:39: error: a function-definition is not allowed here before '{' token
   54 | ll int modInverse(ll int n, ll int p) {
      |                                       ^
a.cc:57:46: error: a function-definition is not allowed here before '{' token
   57 | ll int nCrModP(ll int n, ll int r, ll int p) {
      |                                              ^
a.cc:67:32: error: a function-definition is not allowed here before '{' token
   67 | ll int nCr(ll int n, ll int r) {
      |                                ^
a.cc:78:9: warning: empty parentheses were disambiguated as a function declaration [-Wvexing-parse]
   78 | int main() {
      |         ^~
a.cc:78:9: note: remove parentheses to default-initialize a variable
   78 | int main() {
      |         ^~
      |         --
a.cc:78:9: note: or replace parentheses with braces to value-initialize a variable
a.cc:78:12: error: a function-definition is not allowed here before '{' token
   78 | int main() {
      |            ^
a.cc:94:2: error: expected '}' at end of input
   94 | }
      |  ^
a.cc:10:12: note: to match this '{'
   10 | int main() {
      |            ^