#include <stdio.h>
#include <limits.h>

int main(){
    int n;
    scanf("%d", &n);
    
    int arr[10];
    int hasNegative = 0;
    
    for (int i = 0; i < n; i++){
        scanf("%d", &arr[i]);
        if (arr[i] < 0){
            hasNegative = 1;
        }
    }
    if (hasNegative){
        printf("Invalid Input\n");
        
    }else {
        int minpositive = INT_MAX;
        int found = 0;
        
        for (int i = 0; i < n; i++){
            if (arr[i] > 0 && arr[i] < minPositive) {
                minPositive = arr[i];
                found = 1;
            }
        }
        
        if (found) {
            printf("%d\n", minPositive);
            
        }else {
            printf("Invalid Input\n");
        }
    }
    return 0;