#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
int main()
{
    int m, t, s;
    cin >> m >> t >> s;
    double ans;
    if (t != 0)
    {
        if (s / t > m)
            ans = 0;
        else
            ans = 1.0 * m - 1.0*s / t;
        
    }
    else
        ans = 0;
    cout << ans;
    return 0;
}