#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;
int main(void){
    double a;
    double max=0,min=999999999;
    while(~scanf("%lf",&a)){
        if(max<a)max=a;
        if(min>a)min=a;
    }
    printf("%lf\n",max-min);
}
