func_code_string: #include <bits/stdc++.h>   using namespace std;   inline void readInt(int &num) {     num = 0;     int c = getchar();     int s = 1;     if (c ==  - ) {       s = -1;       c = getchar();     }     while (c >=  0  && c <=  9 ) {       num = num * 10 + (c -  0 );       c = getchar();     }     num *= s;   }   inline void printInt(int num) {     string s =   ;     if (num < 0) {       putchar( - );       num = -num;     }     if (num == 0) putchar( 0 );     while (num) {       s +=  0  + num % 10;       num /= 10;     }     for (int i = s.size() - 1; i >= 0; i--) {       putchar(s[i]);     }   }   inline void readLL(long long &num) {     num = 0;     int c = getchar();     int s = 1;     if (c ==  - ) {       s = -1;       c = getchar();     }     while (c >=  0  && c <=  9 ) {       num = num * 10 + (c -  0 );       c = getchar();     }     num *= s;   }   inline void printLL(long long num) {     string s =   ;     if (num < 0) {       putchar( - );       num = -num;     }     if (num == 0) putchar( 0 );     while (num) {       s +=  0  + num % 10;       num /= 10;     }     for (int i = s.size() - 1; i >= 0; i--) {       putchar(s[i]);     }   }   inline void readString(string &s) {     s =   ;     char c = getchar();     while (c !=     && c !=   n  && c != EOF) {       s += c;       c = getchar();     }   }   inline void readLine(string &s) {     s =   ;     char c = getchar();     while (c !=   n  && c != EOF) {       s += c;       c = getchar();     }   }   inline void printString(const string &s) {     for (int i = 0; i < (int)s.size(); i++) putchar(s[i]);   }   int main() {     int n;     readInt(n);     string str;     string zeroes =   ;     string ugly =   ;     bool is_find = false;     for (int i = 0; i < (int)n; i++) {       string temp;       readString(temp);       if (temp.size() == 1 && temp[0] ==  0 ) {         putchar( 0 );         return 0;       } else if (!is_find) {         if (temp[0] !=  1 ) {           ugly = temp;           is_find = true;         } else if (temp.size() > 1) {           string tz =   ;           for (int i = 1; i < temp.size(); i++)             if (temp[i] !=  0 ) {               ugly = temp;               is_find = true;               break;             } else               tz +=  0 ;           if (!is_find) zeroes += tz;         }       } else if (temp.size() > 1) {         for (int j = 1; j < temp.size(); j++) zeroes +=  0 ;       }     }     string ans = (is_find) ? ugly + zeroes :  1  + zeroes;     printString(ans);     return 0;   }   