def run(I,R):
R = list(map(int,R))
R = sorted(list(set(R)))
R = list(map(str,R))
tmp = [[] for _ in range(len(R))]
for _ii, i in enumerate(I):
for _ri,r in enumerate(R):
if r in i:
tmp[_ri].append(_ii)
res = []
for i,t in enumerate(tmp):
if len(t) > 0:
res.append(R[i])
res.append(str(len(t)))
for _t in t:
res.append(str(_t))
res.append(I[_t])
res = [str(len(res))]+res
return " ".join(res)
I = input().split()[1:]
R = input().split()[1:]
print(run(I,R))