#include <bits/stdc++.h>   using namespace std;   char c[1000];   int i, n, d, t, q;   int main() {     cin >> c;     n = strlen(c);     i = 0;     while (i < n && c[i] !=  @ ) {       if (!isalnum(c[i]) && c[i] !=  _ ) {         cout <<  NO ;         return 0;       }       i++;     }     i++;     t = i;     if (i == n || i > 16 || i < 1) {       cout <<  NO ;       return 0;     }     while (i < n && c[i] !=  / ) {       d = 0;       q = i;       while (i < n && c[i] !=  .  && c[i] !=  / ) {         if (!isalnum(c[i]) && c[i] !=  _ ) {           cout <<  NO ;           return 0;         }         i++;         d = 1;       }       if (i - q > 16 || i - q < 1) {         cout <<  NO ;         return 0;       }       if (c[i] !=  / ) i++;     }     if (i - t > 32 || i - t < 1 || (i == n && c[i - 1] ==  . )) {       cout <<  NO ;       return 0;     }     if (c[i] ==  / ) {       if (i == n) {         cout <<  NO ;         return 0;       }       t = i + 1;       i++;       while (i < n) {         if (!isalnum(c[i]) && c[i] !=  _ ) {           cout <<  NO ;           return 0;         }         i++;       }       if (i - t > 16 || i - t < 1) {         cout <<  NO ;         return 0;       }     }     cout <<  YES ;     return 0;   }   