For all pairs \((i,j)\), check if \(A_{i,j}\) and \(A_{j,i}\) correspond appropriately.

Use double loop to implement it. Beware of the cases where \(i=j\). The implementation may be simplified by terminating the program once a contradictory result has been found.

Sample code (Python)

N=int(input())
A=[input()for i in range(N)]

for i in range(N):
  for j in range(N):
    if i==j:continue
    if A[i][j]=="W":
      if A[j][i]!="L":
        print("incorrect")
        exit()
    elif A[i][j]=="D":
      if A[j][i]!="D":
        print("incorrect")
        exit()
    elif A[i][j]=="L":
      if A[j][i]!="W":
        print("incorrect")
        exit()
print("correct")