#include<bits/stdc++.h>

using namespace std;
typedef long long ll;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define mp make_pair
#define pb push_back
#define lp(i,s,f) for(ll i = s; i < ll(f); i++)
#define inF freopen("input.in", "r", stdin);
#define outF freopen("output.in", "w", stdout);
#define endl '\n'
#define MOD 1000000007
#define mm(arr) memset(arr, 0, sizeof(arr))
#define F first
#define S second

const long double PI = atan(1) * 4.0;

int main(){
    FAST
    int ds = 0;
    int n, d; cin >> n >> d;
    for(int i = 0; i < n; i++){
        int a; cin >> a;
        if(a == d){
            ds++;
        }
    }
    if(ds == 0){
        cout << 0;
        return 0;
    }
    if(d == 0){
        cout << ds;
        return 0;
    }
    cout << ds - (1 - ds%2);
    return 0;
}