N=int(input()) map=[list(map(int,input()))for i in range(N)] ans=[] def dfs(x,y): if x=N or y=N: return False if map[x][y]==1: map[x][y]=2 dfs(x-1,y) dfs(x,y-1) dfs(x+1,y) dfs(x,y+1) return True return False prev=0 cnt=0 for i in range(N): for j in range(N): if dfs(i,j)==1: now=0 cnt+=1 for k in range(N): now+=map[k].count(2) now-=prev ans.append(now) prev+=now ans.sort() print(len(ans)) for i i..