def move_zeros_to_end(arr):
    count=0
    for i in range(len(arr)):
        if arr[i]!=0:
            arr[count]=arr[i]
            count+=1
       while count <len(arr):
           arr[count]=0
           count+=1
          return arr
          
    def solve():
        try:
            N=int(input())
            arr=[]
            for_in range(N):
                arr.append(int(input())
                if 0 not in arr:
                    print("Invalid input")
                else:
                    modified_arr=move_zeros_to_end(arr)
                    print("".join(ap(str,modified_arr)))