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

using namespace std;

int minAbsDiff(vector<int>& arr) {
    sort(arr.begin(), arr.end());
    int minDiff = -1;

    for (int i = 1; i < arr.size(); i++) {
        int diff = arr[i] - arr[i - 1];
        minDiff = (minDiff < 0 || minDiff > diff) ? diff : minDiff;
    }
    return minDiff;
}

int main() {
    int N;
    cin >> N;
    vector<int> arr(N);

    for (int n = 0; n < N; n++) {
        cin >> arr[n];
    }

    cout << minAbsDiff(arr) << endl;
    return 0;
}