def cammino(T,s,d):
    if T[d-1][1] == s:
        return [s]
    else:
        l = []
        l.append(d)
        l.extend(cammino(T,s,T[d-1][1]))
        return l


def distanza(T,s,d):
    if T[d-1][1] == s:
        return T[d-1][2]
    return T[d-1][2] + distanza(T,s,T[d-1][1])


p = [[1, 0, 1], [2, 0, 1], [3, 2, 1], [4, 3, 1], [5, 3, 1], [6, 4, 1], [7, 5, 1]]