#include	<iostream>
#include	<cstdio>

using namespace std;

int main(void) {
	double min = 0.0, max = 0.0, dif, height;
	int count = 0;
	while( scanf("%lf", &height) != EOF ) {
		
		if(count == 0) {
			max = height;
			min = height;
		} else {
			if(height > max) {
				max = height;
			}
			if(height < min) {
				min = height;
			}
		}
		dif = max - min;
		count++;
	}
	cout << dif << endl;
	
	return 0;
}