#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl
inline int power(int a, int b) {
    int x = 1;
    while (b) {
        if (b & 1) x *= a;
        a *= a;
        b >>= 1;
    }
    return x;
}


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

//_ ***************************** START Below *******************************

vector<int> a;

int consistency(int n, int k) {

	vector<int> f(32, 0);
	int oor = 0;
	int ans = n+1;	
	int s = 0, e = 0;
	while(e<n){
	    for(int i=0; i<32; i++){
	        if(a[e]&(1<<i)) f[i]++;
	    }
	    oor |= a[e];	
	    if(oor < k){
	        e++;
	    }
	    else{
	        while(s<=e && oor >= k){
	            ans = min(ans, e-s+1);	
	            int newOr = 0;
	            for(int i=0; i<32; i++){
	                if(a[s]&(1<<i)) f[i]--;
	                if(f[i] > 0) newOr = (newOr | (1<<i));
	            }
	            oor = newOr;
	            s++;
	        }
	        e++;
	    }
	}	
	
	if(ans == n+1) return -1;
	
	return ans;
}









int practice(int n, int k) {
	
	
	return 0;
}


void solve() {
    
    int n, k;
    cin>>n >> k;
	
	a.resize(n);
    for(int i=0; i<n; i++) cin >> a[i];
    
	cout << consistency(n, k) << endl;
	// cout << consistency(n, k) << " -> " << practice(n, k) << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}