#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
  double x, cnt=0;
  vector<double> a;
  while(cin >> x) {
    a.push_back(x);
    cnt++;
  }
  sort(a.begin(), a.end());
  double ans=a[cnt-1]-a[0];
  cout << ans << endl;
  return 0;
}
