#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
ll gcd(ll a, ll b){
    if(b==0) return a;
    return gcd(b, a%b);
}
int main(){
    ll a, b, t;
    cin>>a>>b>>t;
    if(a*b<=t){
        ll d=gcd(a, b);
        cout<<(t+d-1)/d*d<<endl;
    }else{
        ll ans=1e12;
        for(ll i=0; i*b<t+b; i++){
            ans=min(ans, i*b+(max(0ll, t-i*b)+a-1)/a*a);
        }
        cout<<ans<<endl;
    }
    return 0;
}