#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

long long gcd(long long a, long long b){
    return b?gcd(b, a%b):a;
}

long long lcm(long long a, long long b){
    return a*b/gcd(a,b);
}

int main(){
    ll A, B, T;
    cin >> A >> B >> T;

    //ll l = lcm(A, B);
    //ll z = T / l * l;
    //T %= l;
    //debug(z);
    ll z = 0;
    
    ll ans = LLONG_MAX;
    for(ll y = 0; ; ++y){
        ll by = B*y;
        ll x = max(0ll, (T - by + A - 1) / A);
        ll ax = A*x;
        smin(ans, ax + by + z);
        if(by >= T)break;
    }

    cout << ans << endl;
}