水水水
#include <iostream>
#include <algorithm>
using namespace std;
int x, y, m;
int main()
{
cin >> x >> y >> m;
int res = (m / x) * x; //全部小桶
for (int i = 1; i <= m/y; i ++)
res = max(res, ((m - i *y) / x)*x + i * y); //枚举中桶
cout << res << endl;
return 0;
}