#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

bool hasPairSum(const vector<int>& nums, int target) {
    unordered_set<int> seen;
    for (int num : nums) {
        int complement = target - num;
        if (seen.count(complement)) {
            return true;
        }
        seen.insert(num);
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    int n, target;
    if (!(cin >> n >> target)) return 0;
    
    vector<int> nums(n);
    for (int i = 0; i < n; ++i) {
        cin >> nums[i];
    }
    
    if (hasPairSum(nums, target)) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }
    
    return 0;
}

import java.util.*;
import java.io.*;

public class Main {
    public static boolean hasPairSum(int[] nums, int target) {
        Set<Integer> seen = new HashSet<>();
        for (int num : nums) {
            int complement = target - num;
            if (seen.contains(complement)) {
                return true;
            }
            seen.add(num);
        }
        return false;
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        int n = Integer.parseInt(st.nextToken());
        int target = Integer.parseInt(st.nextToken());
        
        int[] nums = new int[n];
        st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) {
            nums[i] = Integer.parseInt(st.nextToken());
        }
        
        if (hasPairSum(nums, target)) {
            System.out.println("YES");
        } else {
            System.out.println("NO");
        }
    }
}

def has_pair_sum(nums, target):
    seen = set()
    for num in nums:
        complement = target - num
        if complement in seen:
            return True
        seen.add(num)
    return False

if __name__ == "__main__":
    import sys
    input = sys.stdin.read
    data = input().split()
    
    n = int(data[0])
    target = int(data[1])
    nums = list(map(int, data[2:2+n]))
    
    if has_pair_sum(nums, target):
        print("YES")
    else:
        print("NO")

function hasPairSum(nums, target) {
    const seen = new Set();
    for (const num of nums) {
        const complement = target - num;
        if (seen.has(complement)) {
            return true;
        }
        seen.add(num);
    }
    return false;
}

const fs = require('fs');
const data = fs.readFileSync(0, 'utf-8').split(/\s+/);
let index = 0;

function readInt() {
    return parseInt(data[index++]);
}

const n = readInt();
const target = readInt();
const nums = [];
for (let i = 0; i < n; i++) {
    nums.push(readInt());
}

if (hasPairSum(nums, target)) {
    console.log("YES");
} else {
    console.log("NO");
}