
import std.stdio;
import std.string;
import std.conv;

void main() {
  double min = int.max.to!(double);
  double max = 0.0;
  string line;
  while((line = readln.chomp).length != 0) {
    double num = line.to!(double);
    if (max < num) max = num;
    else if (min > num) min = num;
  }
  (max - min).writeln;
}