#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
using namespace std;

/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
*/

#define ll long long
#define rep(i, n) for (ll i = 0; i < n; ++i)
#define rep_up(i, a, n) for (ll i = a; i < n; ++i)
#define rep_down(i, a, n) for (ll i = a; i >= n; --i)
#define P pair<ll, ll>
#define pb push_back
#define bit_count(x) __builtin_popcountll(x)
#define gcd(a,b) __gcd(a,b)
#define lcm(a,b) a / gcd(a,b) * b
#define endl "\n"

#define all(v) v.begin(), v.end()
#define fi first
#define se second
#define vvvvll vector< vector <vector <vector<ll> > > >
#define vvvll vector< vector< vector<ll> > >
#define vvll vector< vector<ll> >
#define vll vector<ll>
#define pqll priority_queue<ll>
#define pqllg priority_queue<ll, vector<ll>, greater<ll>>

template<class T> inline void vin(vector<T>& v) { rep(i, v.size()) cin >> v.at(i); }
template <class T>
using V = vector<T>;

template <typename T>
void pt(T val)
{
    cout << val << "\n";
}

//TLE

ll nand(ll x, ll y){
    if(x==1&&y==1) return 0;
    else return 1;
}

void solve(){
    ll n, m, k, cnt = 0, sum = 0, ans = 0;
    cin>>n>>k;
    V<string> s(n);
    cin>>s[0];
    assert(n==s[0].size());
    assert(1<=k&&k<n&&n<=400000);
    rep(i,n-1){
        rep(j,n-i-1){
            ll x=s[i][j]-'0';
            ll y=s[i][j+1]-'0';
            ll z=nand(x,y);
            s[i+1].pb(z+'0');
        }
    }
    /*
    rep(i,n){
        rep(j,n-i-1) cout<<" ";
        rep(j,i+1){
            cout<<s[n-i-1][j];
            cout<<" ";
        }
        cout<<endl;
    }
    */
    pt(s[n-k]);
}   

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    //cout << fixed << setprecision(16);
    //ll T;
    //cin>>T;
    //rep(ca,T)
    solve();
}