#include<stdio.h>
#include<stdlib.h>
void mergeSort(int  arr[],int  temp[],int left,int right);
void merge(int  arr[],int temp[],int left,int right);
int isSorted(int arr[],int n);
int main()
{
    int n;
    scanf("%d",&n);
    if(n<1 || n>100){
        printf("Invalid input\n");
        return 0;
    }
    int prices[n];
    int temp[n];
    for(int i=0;i<n;i++){
        scanf("%d",&prices[i]);
        if(prices[i]<0){
            printf("Invalid input");
            return 0;
        }
        if(isSorted(prices,n)){
            printf("-1\n");
            return 0;
        }
        mergeSort(prices,temp,0,n-1);
        for(int i=0;i<n;i++){
            printf("%d",prices[i]);
        }
        return 0;
    }
    void mergeSort(int arr[],int temp[],int left,int right){
        if(left<right){
            intt mid=(left+right)/2;
            mergeSort(arr,temp,left,mid);
            mergeSort(arr,temp,mid+1,right);
            merge(arr,temp,left,right);
            }
    }
    void merge(int arr[],int temp[],int left,int right){
        int index=left;
        while(leftStart<=mid && rightStack<=right){
            if(arr[leftStack]<=arr[rightStack]){
                temp[index++]=arr[leftStart++];
            }
            else{
                temp[index++]=arr[rightStart++];
            }
        }
        while(leftStart<=mid){
            temp[index++]=arr[leftStart++];
        }
        while(rightStart<=right){
            temp[index++]=arr[rightStart++];
        }
        for(int i=left;i<=right;i++){
            arr[i]=temp[i];
        }
    }
    int isSorted(int arr[],int n){
        for(int i=1;i<n;i++){
            if(arr[i]<arr[i-1]){
                return 0;
            }
        }
        return 1;
    }