#include <stdio.h>

// 二分探索関数
int binary_search(int a[], int n, int x){
    int left = 0;
    int right = n - 1;
    int mid;
	while(left <= right){mid = (left + right) / 2;
		if(a[mid] == x){return mid;}
        else if(a[mid] < x){left = mid + 1;}
        else{right = mid - 1;}}
    return -1;}
int main(){
    int a[100];
    int n, x, i;
    int ans;
    scanf("%d %d", &n, &x);
    for(i = 0; i < n; i++){scanf("%d", &a[i]);}
    ans= binary_search(a, n, x);
	if(ans != -1)  printf("a[%d] = %d\n", ans, a[ans]);
    else printf("not found\n");
		return 0;}