#include<stdio.h>

int main()
{
    int arr[]= {1,2,3,4,5,6,7};
    int tmp,i;
    int left=0,right=sizeof(arr)/sizeof(arr[0])-1;
    int n=right;
    while(left<right)
    {
        tmp=arr[left];
        arr[left]=arr[right];
        arr[right]=tmp;
        left++;
        right--;
    }
    for(i=0; i<=n; i++)
        printf("%d ",arr[i]);
    return 0;
}