G_ACM

#include <iostream>

using namespace std;

int main()
{
    double s, d, n;
    cin >> s >> d >> n;

    int x = 1;
    double temp;

    if (d == 0) cout << "0\n";
    else
    {
        for (int i = 1; i <= 100; i++)
        {
            temp = s;
            for (int j = 0; j < n; j++)
            {
                temp = temp + (temp * i * 0.01);
            }
            if (temp == (s + d)) cout << i << endl;
        }
    }
}