백준 1316 python

n=int(input())
temp=[]
cnt=0
past=0


for i in range(n):
    word=str(input())
    for i in word:
        # print(i)
        if i not in temp or past==i:
            temp.append(i)
            past=i
        else:
            cnt+=1
            break
    past=0
    temp=[]
            
            
print(n-cnt)