#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");
        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){
        int 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 mid=(left+right)/2;
        int leftStart=left,rightStart=mid+1;
        int index=left;
        while(leftStart<=mid && rightStart<=right){
            if(arr[leftStart]<=arr[rightStart]){
                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=0;i<n;i++){
                    if(arr[i]<arr[i-1]){
                        return 0;
                    }
                }
                return 1;
            }