#include <stdio.h>

int main() {
	int data[9] = {1, 2, 4, 4, 4, 6, 7, 8, 10};
	int num = 4;
	int low,high,mid;
	low = 0;
	high = sizeof(data)/sizeof(int) - 1;
    
    while(low <= high){
        mid = (low + high) / 2;
        if(num == data[mid]){
            if(data[mid] == data[mid+1]){
                printf("%d ",mid);
                return 0;
            }
            else{
            high = mid - 1;
        }
        }
    
    else if(num > data[mid]){
        low = mid + 1;
    }
    else if(num < data[mid]){
        high = mid - 1;
    }

    }
    
	return 0;
}