#include<bits/stdc++.h>
using lint=long long;
using real=long double;
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint p,q,a;std::cin>>p>>q>>a;
    if(p<=q){
        std::cout<<(p==q&&a?1'000'000'000:0)<<'\n';
        return 0;
    }
    lint x=((a+p-q-1)/(p-q)-1)*100;
    for(;p*x/100<q*x/100+a;x++);
    std::cout<<x-1<<'\n';
}