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

void main()
{
  size_t n = readln.chomp.to!size_t;
  size_t k = readln.chomp.to!size_t;
  int[] ai = n.iota.map!(_ => readln.chomp.to!int).array;

  int mi = ai.reduce!min;
  int ma = ai.reduce!max;

  writeln(ma - mi);
}