#include    <stdio.h>

int main(void)
{
    int N, X[100000];
    int i, j, min, temp;

    scanf("%d", &N);
    for (i = 0; i < N; i++) {
        scanf("%d", &(X[i]));
    }

    min = 1000001;
    for (i = 0; i < N - 1; i++) {
        for (j = i + 1; j < N; j++) {
            if (X[i] == X[j]) {
                continue;
            } else if (X[i] < X[j]) {
                temp = X[j] - X[i];
            } else {
                temp = X[i] - X[j];
            }
            if (min > temp) {
                min = temp;
            }
        }
    }

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

    return 0;
}