#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <algorithm>
#include <functional>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cctype>
#include <string>

using namespace std;

int x[1000001];
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    int t;
    cin >> t;
    x[t] = 1;
  }
  if (n <= 1) {
    std::cout << 0 << std::endl;
    return 0;
  }
  int ans = 2e9;
  int p = 0;
  while (!x[p]) p++;
  for (int i = p+1; i <= 1000000; i++) {
    if (x[i]) {
      ans = min(ans, i-p);
      p = i;
    }
  }
  if (ans == 2e9) {
    std::cout << 0 << std::endl;
  }else {
    std::cout << ans << std::endl;
  }
}