import std.stdio, std.string, std.conv, std.algorithm;

void main()
{
    real[] heits;
    while(true)
    {
        auto line = readln;
        if(!line)break;
        heits ~= line.chomp.to!real;
    }
    heits.sort;
    (heits[$ - 1] - heits[0]).writeln;
}