#include<iostream>
using namespace std;
int main(){
	int n,x,y;
	cin>>x>>y>>n;
	cout<<n-x-y;
}

#include<iostream>
using namespace std;
int main(){
	int x,y,d;
	cin>>x>>y; 
	d=y/x;
	y=d*5;
	cout<<y;
	return 0;	
}