#include <iostream>
#include <string>
#include <vector>
#include <cstring>
#include <climits>
#include <algorithm>
#include <map>
using namespace std;

int main() {
    int N;
    cin >> N;
    vector<int> X(N);
    for (int i=0; i<N; ++i) {
        cin >> X[i];
    }
    X.erase(unique(X.begin(), X.end()), X.end());
    if ((int)X.size() <= 1) {
        cout << 0 << endl;
    } else {
        sort(X.begin(), X.end());
        int ret = INT_MAX;
        for (int i=1; i<(int)X.size(); ++i) {
            ret = min(ret, abs(X[i] - X[i-1]));
        }
        cout << ret << endl;
    }
    return 0;
}