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class Graph:
    
    adj = []

    # Function to fill empty adjacency matrix
    def __init__(self, v, e):
        
        self.v = v
        self.e = e
        Graph.adj = [[0 for i in range(v)] 
                        for j in range(v)]

    # Function to add an edge to the graph
    def addEdge(self, start, e):
        
        # Considering a bidirectional edge
        Graph.adj[start][e] = 1
        Graph.adj[e][start] = 1

    # Function to perform BFS on the graph
    def BFS(self, start):
        
        ans = []
        # Visited vector to so that a
        # vertex is not visited more than 
        # once Initializing the vector to 
        # false as no vertex is visited at
        # the beginning 
        visited = [False] * self.v
        q = [start]

        # Set source as visited
        visited[start] = True

        while q:
            vis = q[0]

            # Print current node
            ans.append(str(vis))
            q.pop(0)
            
            # For every adjacent vertex to 
            # the current vertex
            for i in range(self.v):
                if (Graph.adj[vis][i] == 1 and
                    (not visited[i])):
                        
                    # Push the adjacent node 
                    # in the queue
                    q.append(i)
                    
                    # set
                    visited[i] = True
                    
        return " ".join(ans)

n = int(input())

for i in range(n):
    
    m = int(input())
    graf = Graph(m, m)
    
    for j in range(m):
        
        line = input()
        
        for k in range(m):
            if line[k] == '1':
                graf.addEdge(k, j)
                
    ans = graf.BFS(i)
    print(int(ans.split()[0]) + 1)