func_code_string: #include <bits/stdc++.h>   bool x[1000000] = {0};   int a, b, c;   int y[10001];   int main() {     for (a = 2; a < 1001; a++) {       if (x[a] == 0) {         for (b = a * a; b < 1000000; b = b + a) x[b] = 1;       }     }     int qqq[11200];     int p, q, k, z, r, s = 1, t = 13;     while (s != 11185) {       k = t;       p = 0;       while (k >= 10) {         y[p] = k % 10;         k = k / 10;         p++;       }       y[p] = k;       z = 0;       for (r = 0; r <= p; r++) z = z * 10 + y[r];       if (x[t] == 0 && x[z] == 0 && t != z) {         qqq[s] = t;         s++;       }       t++;     }     while (scanf( %d , &c) == 1) {       printf( %d n , qqq[c]);     }     return 0;   }   