import std.stdio;
import std.string : chomp;
import std.conv : to;
import std.math : round;



void main() {
    string input;
    double highest=0, lowest=1000000;

    while ((input = readln.chomp).length != 0) {
        double temp = input.to!double;

        if (temp > highest) highest = temp;
        if (temp < lowest)  lowest  = temp;
    }

    writeln(((highest - lowest) * 100).round / 100);
}