来喽

using namespace std;
int main(){
	int n;
	int x;
	int y;
	cin>>n>>x>>y;
	if(y%x!=0){
		cout<<n-y/x-1;
	}
	else{
		if(n-y/x<=0){
		cout<<"0";
	}
	else{
	cout<<n-y/x;}
	}
	return 0;
}