import std.stdio,
       std.conv,
       std.string,
       std.range,
       std.math,
       std.bigint,
       std.algorithm,
       core.bitop;

void main()
{
    auto N = readln.chomp.to!int;
    auto K = readln.chomp.to!int;
    auto n = stdin.byLineCopy.array.to!(int[]);

    (n.reduce!max - n.reduce!min).writeln;
}