#include <stdio.h>
#include <algorithm>
int N;
int main(){
    //input
    scanf("%d",&N);
    int X[N];
    for (int i = 0;i < N;i++){
        scanf("%d",&X[i]);
    }

    //sort X array
    std::sort(X,X+N);

    //search
    int min = 1000001;
    for (int i = 0;i <= N-2;i++){
        if (X[i] != X[i+1] && X[i+1]-X[i] < min){
            min = X[i+1]-X[i];
        }
    }

    //ouput
    if (min == 1000001){
        printf("%d\n",0);
    }else{
        printf("%d\n",min);
    }
    return 0;
}