func_code_string: #include <bits/stdc++.h>   using namespace std;   long long mod = 1e9 + 7;   long long fact[1100000];   void find_fact() {     fact[0] = fact[1] = 1;     for (int i = 2; i <= 1e6; i++) fact[i] = (i * fact[i - 1]) % mod;   }   bool isvalid(long long num, int num1, int num2) {     while (num > 0) {       int cval = (num % 10);       if ((cval != num1) && (cval != num2)) return 0;       num = (num / 10);     }     return 1;   }   long long my_exp(int base, int exp) {     if (exp == 0) return 1;     if (exp == 1) return base;     long long ans = my_exp(base, exp / 2);     ans = (ans * ans) % mod;     if (exp % 2) ans = (ans * base) % mod;     return ans;   }   long long my_comb(int n, int i) {     return (fact[n] * my_exp((fact[i] * fact[n - i]) % mod, mod - 2)) % mod;   }   int main() {     find_fact();     int num1, num2, n;     cin >> num1 >> num2 >> n;     long long csm, ans = 0;     for (int i = 0; i <= n; i++) {       csm = (i * num1 + (n - i) * num2);       if (isvalid(csm, num1, num2)) ans = (ans + my_comb(n, i)) % mod;     }     cout << ans;     return 0;   }   