def DFS(G):
    stack = []
    visited = [ 0 for i in range(len(G)) ]
    stack.append(0)
    while len(stack) > 0:
        current = stack.pop()
        visited[current] = 1
        print(current, end=" ")
        for j in reversed(range(len(G))):
            if G[current][j] == 1 and visited[j] == 0:
                stack.append(j)

DFS([ [0,0,1,0,1,1,0], [0,0,1,1,0,1,0], [1,1,0,1,1,1,0], [0,1,1,0,0,0,0],
      [1,0,1,0,0,0,1], [1,1,1,0,0,0,0], [0,0,0,0,1,0,0] ])