#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n)  FOR(i,0,n)

int main(){
    int A,B,T;
    cin >> A >> B >> T;
    int total = 0;
    int hoge;

    if(A<B){
        hoge = A;
        A = B;
        B = hoge;
      }

    for(int i=ceil((double)T/(double)A);i>=0;i--){
        if(T -total == 0) break;
        if(abs(T-total) > abs(T-(i*A+ B*ceil((double)(T-i*A)/(double)B)))){
            total = (i*A+ B*ceil((T-i*A)/(double)B));
        }
    }
    total = total == 0 ? B : total;
    cout << total << endl;

    return 0;
}