def solution(skill, skill_trees):
skill = list(skill)
answer = 0
for i in skill_trees:
stack = []
for j in i:
if j in skill:
stack.append(j)
count = 0
for k in range(len(stack)):
if stack[k] == skill[k]:
count += 1
else:
break
if count == len(stack):
answer += 1
return answer