dfs, 알파벳 배열 생성 후 방문 체크 import sys input=sys.stdin.readline R,C=map(int,input().split()) board=[list(input().strip()) for _ in range(R)] dirs=[(1,0),(0,1),(-1,0),(0,-1)] alpha=[0]*26 answer=0 def dfs(row,col,cnt): global answer answer=max(answer,cnt) for i in range(4): nr,nc=row+dirs[i][0],col+dirs[i][1] if 0