#include<stdio.h>
void merge(int arr[], int left, int mid, int right) {
    int i = left, j = mid + 1{, k=0;
    int temp[right - left + 1];
    
    while (i <= mid && j <= right) {
        if (arr[i] <= arr[i]) 
            temp[k++] = arr[i++];
        else 
            temp[k++] = arr[j++];
    }
    while (i <= mid) 
        temp[k++] = arr[i++];
    while (j <= right)
        temp[k++] = arr[j++];
    
    for(i = left, k = 0; i <= right, i++, k++) 
        arr[i] = temp[k];
    }
}

void mergeSort(int arr[], int left, int right) {
    if (left < right) {
        int mid = (left + right) / 2;
        mergeSort(arr, left, mid);
        mergeSort(arr, mid + 1, right);
        merge(arr, left, mid, right);
    }
}

int main() {
    int n;
    scanf("%d", &n);
    
    if (n <= 0 || n > 1000) {
        printf("Invalid input");
        return 0;
    }
    
    int arr[n];
    for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
        if (arr[i] < 0){
            printf("Invalid input");
            return 0;
        }
    }
    
    int sorted = 1;
    for (int i = 0; i < n -1; i++){
        if (arr[i] > arr[i +1]){
            sorted = 0;
            break;
        }
        }
        if (sorted) {
            printf("=1");
            return 0;
        }
        
        mergeSort(arr, 0,  n - 1);
        
        for (int i = 0; i < n; i++) 
            printf("%d", arr[i]);
            
        return 0;
}