#include <bits/stdc++.h>
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define all(x) x.begin(), x.end()
using namespace std;
using ll=long long;
using ld=long double;
using P=pair<ll,ll>;
#include <atcoder/all>
using namespace atcoder;
//using mint=static_modint<998244353>;
using mint=static_modint<1000000007>;


int main(){
	ll a,b,x;cin>>a>>b>>x;
    ll cru=0;
    ll ans=0;
    while(x>cru){
        cru+=a;
        ans+=b;
    }
    cout<<ans<<endl;
}