#include<cstdio>
#include<iostream>
using namespace std;
int main(){
double max=-1,min=-1,n;
while(scanf("%lf",&n)!=EOF){
if(n>max||max==-1){
max=n;
}
if(n<min||min==-1){
min=n;
}
}
cout<<max-min<<endl;
}