from collections import deque
    

def topView(root):
    
    result = {}
    
    bfs = deque()
    bfs.append((root, 0))
    
    while bfs:
        node, distance = bfs.popleft()
        
        if distance not in result:
            result[distance] = node.info
            
        if node.left:
            bfs.append((node.left, distance - 1))
        
        if node.right:
            bfs.append((node.right, distance + 1))
        
    result = dict(sorted(result.items()))
    print(" ".join(map(str, result.values())))