#include <stdio.h>
#include <stdlib.h>
 
int binaly_search(int a[],int n,int x){
	int mid,lef,rig,i;
	int ret=-1;
	lef=0;
	rig=n-1;
	for(i=0;i<n;i++){
		if(lef<=rig){
		mid=(lef+rig)/2;
		}
		if(a[mid]==x){
			ret=mid;
			break;
		}
		if(a[mid]<x){
			lef=mid+1;
		}
		else{
			rig=mid-1;
		}
	}
	return ret;
}
 
int main(void){
	int i,n,x;
	int *a;
	int ans=-1;
	scanf("%d %d",&n,&x);
	a=(int *)malloc(sizeof(int)*n);
	if(a==NULL){
		printf("ERROE\n");
		return -1;
	}
	for(i=0;i<n;i++){
		scanf("%d",&a[i]);
	}
	ans=binaly_search(a,n,x);
	if(ans!=-1){
		printf("a[%d]=%d\n",ans,a[ans]);
	}
	else{
		printf("not found\n");
	}
	free(a);
	return 0;
}

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