#include <stdio.h>
#include <limits.h>
int main() {
    int n, i;
    int num;
    int min_val = INT_MAX;
    int ha_invalid_input = 0;
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        scanf("%d",&num);
        if (num < 0) {
            has_invalid_inpput = 1;
        }
        if (num > 0 && num < min_val) {
            min_val = num;
        }
    }
    if (has_invalid_input) {
        printf("Invalid Input\n");
    } else {
        printf("%d\n",min_val);
    }
    return 0;
}