#include <bits/stdc++.h>

#define loop(v, f, l) for(int v = (f), v##_ = (l); v < v##_; ++v)

using namespace std;

typedef long long int lint;
static inline int in(){ int x; scanf("%d", &x); return (x); }
static inline lint inl(){ lint x; scanf("lld", &x); return (x); }

int main()
{
	double highest = 0.0;
	double lowest = DBL_MAX;
	double height;

	while( scanf("%lf", &height) != EOF )
	{
		if( height < lowest )lowest = height;
		if( height > highest ) highest = height;
	}
	printf("%.1lf\n", highest - lowest);
	return (0);
}