func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, a[100010], g, cnt;   int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }   int main() {     scanf( %d , &n);     for (int i = 0; i < n; i++)       scanf( %d , &a[i]), g = g == 0 ? a[i] : gcd(a[i], g), cnt += a[i] & 1;     printf( %d n , cnt > 1 ? 0 : g);     string str, ans;     for (int i = 0; i < n; i++)       for (int j = 1; j <= a[i] / g / 2; j++) str = str + char( a  + i);     for (int i = 0; i < n; i++)       if (a[i] / g & 1) str = str + char(i +  a );     for (int i = n - 1; i >= 0; i--)       for (int j = 1; j <= a[i] / g / 2; j++) str = str + char(i +  a );     while (g--) ans = ans + str, reverse(str.begin(), str.end());     return cout << ans, 0;   }   