#include <stdio.h>
 
int binary_search(int a[], int n, int x){
    int left = 0, right = n - 1, mid;
 
    while(left <= right){
        mid = (left + right) / 2;
 
        if(a[mid] == x){
            return mid;
        }else if(x < a[mid]){
            right = mid - 1;
        }else{
            left = mid + 1;
        }
    }
    return -1;
}
 
int main(){
    int n, x, a[100], i, 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;
}

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