func_code_string: #include <bits/stdc++.h>   using namespace std;   string s;   string name, host, sour;   int main() {     ios::sync_with_stdio(false);     cin >> s;     int i = 0;     while (i < s.size() && s[i] !=  @ ) {       name.push_back(s[i]);       i++;     }     i++;     while (i < s.size() && s[i] !=  / ) {       host.push_back(s[i]);       i++;     }     bool exist = 0;     if (s[i] ==  / ) exist = 1;     i++;     if (i != s.size() + 1)       while (i < s.size()) {         sour.push_back(s[i]);         i++;       }     if (sour.size() > 16 || name.size() == 0 || name.size() > 16 ||         host.size() > 32 || host.size() == 0) {       cout <<  NO n ;       return 0;     }     if (exist && sour.size() == 0) {       cout <<  NO n ;       return 0;     }     for (int j = 0; j < name.size(); j++) {       char c = name[j];       if (!isdigit(c) && !isalpha(c) && (c !=  <  && c !=  >  && c !=  _ )) {         cout <<  NO n ;         return 0;       }     }     int cnt = 0;     for (int j = 0; j < host.size(); j++) {       char c = host[j];       if (!isdigit(c) && !isalpha(c) &&           (c !=  <  && c !=  >  && c !=  .  && c !=  _ )) {         cout <<  NO n ;         return 0;       }       if (c ==  . ) {         if (cnt == 0) {           cout <<  NO n ;           return 0;         }         cnt = -1;       }       cnt++;       if (cnt > 16) {         cout <<  NO n ;         return 0;       }     }     if (cnt == 0) {       cout <<  NO n ;       return 0;     }     for (int j = 0; j < sour.size(); j++) {       char c = sour[j];       if (!isalpha(c) && !isdigit(c) && (c !=  <  && c !=  >  && c !=  _ )) {         cout <<  NO n ;         return 0;       }     }     cout <<  YES n ;     return 0;   }   