mod = 998244353
eps = 10**-9


def main():
    import sys
    from itertools import combinations
    input = sys.stdin.readline

    N = int(input())
    A = []
    PE = []
    P = {}
    for i in range(N):
        M = int(input())
        a = 1
        D = {}
        for j in range(M):
            p, e = map(int, input().split())
            if p not in P:
                P[p] = 0
            P[p] = max(P[p], e)
            a *= p ** e
            D[p] = e
        A.append(a)
        PE.append(D)

    B = []
    for i in range(N):
        D = PE[i]
        b = set()
        for p in D:
            if D[p] == P[p]:
                b.add(p)
        B.append(b)

    L = len(P)
    P_list = list(P.keys())
    for k in range(2, L+1):
        for J in combinations(P_list, k):
            J = list(J)
            ans = [[] for _ in range(k)]
            flg = 1
            for i, b in enumerate(B):
                ok = 0
                for j, pp in enumerate(J):
                    if pp not in b:
                        ans[j].append(A[i])
                        ok = 1
                        break
                if not ok:
                    flg = 0
                    break
            if flg:
                print(k)
                for a in ans:
                    a = [len(a)] + a
                    print(*a)
                exit()
    print(-1)


if __name__ == '__main__':
    main()