Level2 영어 끝말잇기

def solution(n, words):
    a = []
    k = len(words)
    count=0; change=0
    
    for i in range(k-1):
        m = len(words[i])
        if(a.count(words[i])==0 and a.count(words[i+1])==0 and words[i][m-1]==words[i+1][0]): 
            a.append(words[i]); count+=1 
        else: change=1; break    

    ans = count+2
    p = ans%n
    q = ans//n+1
    if(p==0): p=n; q=ans//n
        
    if(change==0): return [0,0]    
    return [p,q]