import sys
from collections import deque

def main():
    V, D = map(int, sys.stdin.readline().split())
    E = []
    for _ in range(V):
        row = sys.stdin.readline().strip()
        E.append([int(c) for c in row])
    
    # Check outdegree
    for i in range(V):
        if sum(E[i]) == 0:
            print("No")
            return
    
    # Build adjacency list for undirected graph
    adj = [[] for _ in range(V)]
    for i in range(V):
        for j in range(V):
            if E[i][j] == 1:
                adj[i].append(j)
    
    # Check connectivity using BFS
    visited = [False] * V
    q = deque()
    q.append(0)
    visited[0] = True
    while q:
        u = q.popleft()
        for v in adj[u]:
            if not visited[v]:
                visited[v] = True
                q.append(v)
    if not all(visited):
        print("No")
        return
    
    # Check bipartiteness using BFS
    color = [-1] * V
    is_bipartite = True
    for i in range(V):
        if color[i] == -1:
            q = deque()
            q.append(i)
            color[i] = 0
            while q:
                u = q.popleft()
                for v in adj[u]:
                    if color[v] == -1:
                        color[v] = color[u] ^ 1
                        q.append(v)
                    elif color[v] == color[u]:
                        is_bipartite = False
                        break
                if not is_bipartite:
                    break
            if not is_bipartite:
                break
    if is_bipartite:
        print("No")
        return
    
    print("Yes")

if __name__ == "__main__":
    main()