#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; if(a<=0){ cout<<0;}else{ cout<<a;} }else{ a=a+n-y/x-1; if(a<=0){ cout<<0; } cout<<a; } return 0;}