func_code_string: #include <bits/stdc++.h>   using namespace std;   const int INF = 1000000009;   const double PI = acos(-1.0);   const double eps = 1e-8;   const int MAXN = 0;   const int MAXM = 0;   long long n, k, t, b, z;   int main() {     z = 1;     int ans = 0;     cin >> k >> b >> n >> t;     while (z <= t) {       ans++;       z = z * k + b;     }     if (z == t)       ans = n - ans;     else {       ans--;       ans = n - ans;     }     cout << max(0, ans) << endl;     return 0;   }   