func_code_string: #include <bits/stdc++.h>   using namespace std;   const double pi = 2 * acos(0.0);   long long int pow1(long long int n, long long int k) {     long long int ret = 1;     while (k) {       if (k % 2 == 1) ret = (ret * n) % 1000000007;       n = (n * n) % 1000000007;       k /= 2;     }     return ret;   }   string s, s1;   int n;   string q[100000];   long long int A[10], len[10];   int main() {     cin >> s;     cin >> n;     for (int i = 0; i < n; i++) cin >> q[i];     for (int i = 0; i < 10; i++) {       A[i] = i;       len[i] = 1;     }     for (int i = n - 1; i >= 0; i--) {       int idx = q[i][0] -  0 ;       long long int val = 0, val1 = 0;       for (int j = 3; j < q[i].size(); j++) {         int d = q[i][j] -  0 ;         val = (val * pow1(10, len[d])) % 1000000007;         val += A[d];         val %= 1000000007;         val1 += len[d];         val1 %= (1000000007 - 1);       }       A[idx] = val;       len[idx] = val1;     }     long long int ans = 0;     for (int i = 0; i < s.size(); i++) {       int d = s[i] -  0 ;       ans = (ans * pow1(10, len[d]) + A[d]) % 1000000007;     }     printf( %lld n , ans);     return 0;   }   