#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

int main() {
  int N, *X;
  char *line;

  scanf("%d\n", &N);
  X = (int *)malloc(sizeof(int) * N);

  int length = 6*N + N-1;
  line = (char *)malloc(sizeof(char) * length);
  fgets(line, length, stdin);

  char *delim = " \n";
  char *tok;
  int i = 0;

  tok = strtok(line, delim);
  while(tok != NULL) {
    X[i] = atoi(tok);
    tok = strtok(NULL, delim);
    i++;
  }

  int j = 0;
  int answer = 1000001; // instead of +INF
  for (i = 0; i < N; i++) {
    int min = 1000001;
    for (j = i+1; j < N; j++) {
      if (X[i] == X[j]) continue;
      int dist = abs(X[i] - X[j]);
      min = dist < min ? dist : min;
    }
    answer = answer < min ? answer : min;
  }

  if (answer == 1000001) answer = 0;
  printf("%d\n", answer);

  free(X);
  free(line);
  return 0;
}