#include<stdio.h>
int A[10]={0,1,2,3,4,5,6,7,8,9};
int Bsearch(int low,int high,int x)
{
int mid;
while(low<=high)
{
mid=(low+high)/2;
if(A[mid]==x)
return mid+1;
else if(A[mid]>x)
{
high=mid-1;
}
else low=mid+1;
}
return 0;
}
int main()
{
int b=Bsearch(0,9,9);
printf("%d\n",b);
}