#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

#define MOD 1000000007
#define REP(i, N) for (int i = 0; i < N; ++i)
#define REP1(i, N) for (int i = 1; i <= N; ++i)
#define RREP(i, N) for (int i = N - 1; i >= 0; --i)
#define ALL(a) a.begin(), a.end()

int main() {
  double mx = -1.0;
  double mn = 1000001.0;
  double n;
  while (cin >> n) {
    mx = max(mx, n);
    mn = min(mn, n);
  }
  cout << mx - mn << endl;
  return 0;
}
