#include <bits/stdc++.h>
using namespace std;

int main() {
    vector<int> heights;
    int height;

    while (cin >> height && height != 11111) {
        heights.push_back(height);
    }

    int leftPointer = 0;
    while (heights[leftPointer] != 0) {
        leftPointer++;
    }

    int rightPointer = heights.size() - 1;
    while (heights[rightPointer] != 0) {
        rightPointer--;
    }

    vector<int> visibleTrees;
    for (int i = leftPointer + 1; i < rightPointer; i++) {
        if (heights[i] != 0) {
            visibleTrees.push_back(heights[i]);
        }
    }
    sort(visibleTrees.begin() , visibleTrees.end());
    int maxHeight = visibleTrees.back();
    int minHeight = visibleTrees.front();

    cout << maxHeight - minHeight << endl;

    return 0;
}