solution

a.cpp

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1000000;

int n, x;
int a[MAXN+10];

bool findX(int i){
	if(i >= n)
		return false;
	if(a[i] == x)
		return true;
	else
		return findX(i+1);
}

int main(){
	cin >> n;
	for(int i = 0; i < n; i++){
		cin >> a[i];
	}
	cin >> x;
	if(findX(0))
		cout << "Yes";
	else
		cout << "No";
	return 0;
}