#include 
#include 
using namespace std;

int main() {
    int p1, p2, p3;
    cin >> p1 >> p2 >> p3;
    
    int x = p2 - p1;
    if(p2 + x == p3) {
        cout << p3 + x << endl;
    }
    else {
        x = p2 / p1;
        cout << p3 * x << endl;
    }
    return 0;
}