#include <stdio.h>

int main()
{
  int n, x[1000001], d, min = 1000001, i, j, k;

  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &x[i]);
  }
  for (j = 0; j < n; j++) {
    for (k = (j + 1); k < n; k++) {
      if (x[j] == x[k]) {
        continue;
      } else {
        d = x[j] - x[k];
        if (d < 0)
          d *= -1;
        if (d < min)
          min = d;
      }
    }
  }
  if (min == 1000001)
    min = 0;
  printf("%d\n", min);

  return 0;
}