#include <bits/stdc++.h> using namespace std; using ll = long long; using llu = long long unsigned; int main() { int a, b, x; cin >> a >> b >> x; int ret = 0; for (int i=1; i*a<x; ++i) { ret = i; } if (ret*a < x) { ret++; } cout << ret * b << endl; return 0; }