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

#define ArraySize 1000001

int main(void){
		int Array1[ArraySize];
		int Array2[ArraySize];
		for(int i = 0;i < ArraySize;i++){
				Array1[i] = -1;
				Array2[i] = -1;
		}
		int n = 0;
		int x = 0;
		int k = 0;
		int y = 1000000;

		scanf("%d", &n);
		for(int j = 0;j < n;j++){
				scanf("%d", &x);
				for(int i = 0;i < ArraySize;i++){
						if(i == x){
								Array1[i] = x;
						}
				}
		}

		for(int i = 0;i < ArraySize;i++){
				if(Array1[i] != -1){
						Array2[k] = Array1[i];
						k++;
				}
		}

		if(k==1){
				printf("0\n");
				return 0;
		}
		
		for(int i = k-1;i > 0;i--){
				if(Array2[i]-Array2[i-1] < y){
						y = Array2[i]-Array2[i-1];
				}
		}

		printf("%d\n", y);

		return 0;
}