int main()
{
int num;
printf("please input the num:\n");
scanf("%d",&num);
int tmp=num;
int index=0,i=0;
while(tmp)
{
tmp/=10;
index++;
}
//printf("%d\n",index);
int arr[index];
while(1)
{
if(num==0)
break;
arr[i]=num%10;
i++;
num/=10;
}
printf("%d%d",arr[index-1],arr[index-2]);
printf("\n");
return 0;
}
