#include<iostream>
#include<vector>
int main(){
	float n,max=0,mini=10000000;
	std::vector<int> high;
	while(1){
		std::cin>>n;
		high.push_back(n);
		if(std::cin.eof())break;
		//if(n==1000)break;
		if(n>max)max=n;
		if(n<mini)mini=n;
	}
	std::cout<<max-mini<<std::endl;
}