#include <stdio.h>
int a[]={1,22,56,77,89,156,189,564,1024,2015,4412};
void mid_search(int left,int right,int digit)
{
if(left>right){printf("Not find!\n");return;}
int mid=left+(right-left)/2;
if(a[mid]==digit) printf("这个数字的数组下标是%d\n",mid);
else if(a[mid]>digit) mid_search(left,mid-1,digit);
else if(a[mid]<digit) mid_search(mid+1,right,digit);
}
int main()
{
int n;
while(~scanf("%d",&n))
mid_search(0,sizeof(a)/sizeof(int)-1,n);
return 0;
}