#include<iostream> using namespace std; int main(){ int n,x,y,a=0; cin>>n>>x>>y; if(y%x==0){ a=a+n-y/x; cout<<a; if(a<0){ cout<<0;} }else{ if(a<0){ cout<<0;} a=a+n-y/x-1; cout<<a; } return 0;}