#line 2 "/home/cocojapanpan/Procon_CPP/proconLibrary/lib/template/procon.hpp"

#ifndef DEBUG
// 提出時にassertはオフ
#ifndef NDEBUG
#define NDEBUG
#endif
// 定数倍高速化
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif

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

#define ALL(x) (x).begin(), (x).end()
template <class T>
using vec = vector<T>;
template <class T, class S>
inline bool chmax(T &a, const S &b) {
    return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
    return (a > b ? a = b, 1 : 0);
}
template <class T>
constexpr T INF = 1'000'000'000;
template <>
constexpr int INF<int> = 1'000'000'000;
template <>
constexpr ll INF<ll> = ll(INF<int>) * INF<int> * 2;
#line 2 "main.cpp"

array<array<bool, 256>, 256> canSeperate;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, M;
    cin >> N >> M;
    for(int i = 0; i < M; i++) {
        vec<int> zero, one;
        for(int j = 0; j < N; j++) {
            char x;
            cin >> x;
            if(x == '0') zero.push_back(N - 1 - j);
            else one.push_back(N - 1 - j);
        }
        for(int a : zero) {
            for(int b : one) {
                canSeperate[min(a, b)][max(a, b)] = true;
            }
        }
    }
    for(int i = 0; i < N - 1; i++) {
        for(int j = i + 1; j < N; j++) {
            if(!canSeperate[i][j]) {
                cout << "No\n";
                return 0;
            }
        }
    }
    cout << "Yes\n";
}