#!/usr/bin/env python
#coding:utf8

def read():
    raw_input()
    return map(int, raw_input().split())


def work(vList):
    vList.sort()

    minV = 1 << 30
    for i in range(len(vList) - 1):
        if vList[i] != vList[i + 1]:
            minV = min(minV, vList[i + 1] - vList[i])

    print 0 if minV == (1 << 30) else minV


if __name__ == "__main__":
    work(read())