#include <bits/stdc++.h> #include <boost/dynamic_bitset.hpp> using namespace std; #define MAX_LEN 1000 using bs = boost::dynamic_bitset<>; vector<bs> prod(const vector<bs>& A, const vector<bs>& B) { int v = A.size(); vector<bs> X(v, bs(v)); for(int i=0;i<v;++i){ for(int j=0;j<v;++j){ for(auto k = A[i].find_first(); k != A[i].npos; k = A[i].find_next(k)){ if(!B[k][j])continue; X[i].set(j); break; } } } //for (int i = 0; i < v; ++i) { // for (auto j = A[i].find_first(); j != A[i].npos; j = A[i].find_next(j)) { // X[i] |= B[j]; // } //} return X; } int main() { int v, d; cin >> v >> d; d = min(d, v * 2); vector<bs> E(v, bs(v)); for (auto& i : E) { string str; cin >> str; reverse(str.begin(), str.end()); i = bs(str); } const int pwrdp = 11; // 2^11 > 2V > 2^10 vector<vector<bs>> dp(pwrdp, vector<bs>(v, bs(v))); dp[0] = E; for (int i = 1; i < pwrdp; ++i) { dp[i] = prod(dp[i - 1], dp[i - 1]); } vector<bs> Rchbl(v, bs(v)); for (int i = 0; i < v; ++i) Rchbl[i].set(i); for (int di = 0, dd = d; dd > 0; ++di, dd /= 2) { if (dd & 1) Rchbl = prod(Rchbl, dp[di]); } for (int i = 0; i < v; ++i) if ((int)Rchbl[i].count() < v) return cout << "No" << endl, 0; cout << "Yes" << endl; return 0; }