func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   long long pw[19];   long long val[19];   char A[100009];   string s[100009];   int main() {     scanf( %s , A);     scanf( %d , &m);     for (int i = 0; i < 10; i++) {       val[i] = i;       pw[i] = 10;     }     for (int i = 0; i < m; i++) cin >> s[i];     for (int j = m - 1; j >= 0; j--) {       int ln = s[j].length();       int nm = s[j][0] -  0 ;       long long nmpw = 1;       long long san = 0;       for (int i = ln - 1; i > 2; i--) {         san = (san + (nmpw * val[s[j][i] -  0 ])) % 1000000007;         nmpw = (nmpw * pw[s[j][i] -  0 ]) % 1000000007;       }       val[nm] = san;       pw[nm] = nmpw;     }     int ln = strlen(A);     long long ans = 0;     long long nmpw = 1;     for (int i = ln - 1; i >= 0; i--) {       ans = (ans + (val[A[i] -  0 ] * nmpw)) % 1000000007;       nmpw = (nmpw * pw[A[i] -  0 ]) % 1000000007;     }     printf( %lld n , ans);   }   