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

#define ALL(x) (x).begin(),(x).end()

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> x(n);
    for(int i = 0;i < n;i++){
        cin >> x[i];
    }
    sort(ALL(x));
    int ans = 1000000;
    for(int i = 2;i < n;i++){
        if(ans > x[i]-x[i-1] && x[i] != x[i-1])ans = x[i]-x[i-1];
    }
    if(ans == 1000000)ans = 0;
    cout << ans << endl;
    return 0;
}