import sys
from collections import deque

def main():
    sys.setrecursionlimit(1 << 25)
    V, D = map(int, sys.stdin.readline().split())
    edges = []
    for _ in range(V):
        s = sys.stdin.readline().strip()
        row = [int(c) for c in s]
        edges.append(row)
    
    # Check connectivity
    visited = [False] * V
    q = deque()
    q.append(0)
    visited[0] = True
    while q:
        u = q.popleft()
        for v in range(V):
            if edges[u][v] and not visited[v]:
                visited[v] = True
                q.append(v)
    if not all(visited):
        print("No")
        return
    
    # Check bipartiteness
    color = [-1] * V
    is_bipartite = True
    for start in range(V):
        if color[start] == -1:
            color[start] = 0
            q = deque()
            q.append(start)
            while q:
                u = q.popleft()
                for v in range(V):
                    if edges[u][v]:
                        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
    else:
        print("Yes")

if __name__ == '__main__':
    main()