#include <bits/stdc++.h>
using namespace std;
int main(void) {
  float low = 1000000, high = 0, yama;
  while (1) {
    cin >> yama;
    if (high < yama)
      high = yama;
    else if (low > yama)
      low = yama;
  }
  cout << high - low << endl;
  return 0;
}
