#include<stdio.h>
void merge(int arr[], int l, int m, int r){
    int n1 = m - l + 1, n2 = r - m;
    int L[n1], R[n2];
    for(int i = 0; i < n1; i++)
        L[i] = arr[left + i];
    for(int j = 0; j < n2; j++)
        R[j] = arr[mid + 1 +j];
    
    int i = 0, j = 0, k = l;
    
    while (i < n1 && j < n2)
    arr[k++] = (L[i] <= R[j]) ? L[i++] : R[j++];
    while (i < n1) arr[k++] = L[i++];
    while (j < n2) arr[k++] = R[j++];
}
void mergeSort(int arr[], int l, int r){
    if(l < r){
        int m = (l + r)/ 2;
        mergeSort(arr, l, m);
        mergeSort(arr, m + 1, r);
        merge(arr, l, m, r);
    }
}
int isSorted(int arr[], int n){
    for(int i = 0; i < n; i++)
    if(arr[i] < arr[i - 1]) return 0;
    return 1;
}
int main(){
    int n;
    scanf("%d", &n);
    int arr[n];
    for(int i = 0; i < n; i++){
        scanf("%d", &arr[i]);
        if(arr[i] < 0){
        printf("Invalid input\n");
        return 0;
        }
    }
    if(isSorted(arr, n)){
        printf("-1");
        return 0;
    }
    
   mergeSort(arr, 0, n - 1);
    
    for(int i = 0; i < n; i++){
        printf("%d", arr[i]);
     return 0;   
}