You are given three strings A, B and C. Each of these is a string of length N consisting of lowercase English letters.  Our objective is to make all these three strings equal. For that, you can repeatedly perform the following operation:    * Operation: Choose one of the strings A, B and C, and specify an integer i between 1 and N (inclusive). Change the i-th character from the beginning of the chosen string to some other lowercase English letter.  What is the minimum number of operations required to achieve the objective?
N = int(input())
A = input()
B = input()
C = input()
cnt = 0
for i in range(N):
  if A[i] == B[i] == C[i]:
    cnt += 0
  elif A[i] != B[i] != C[i]:
    cnt += 2
  else:
    cnt += 1
print(cnt)
N = int(input())
A = input()
B = input()
C = input()
cnt = 0
for i in range(N):
  if A[i] == B[i] == C[i]:
    cnt += 0
  elif A[i] != B[i] and B[i] != C[i] and C[i] != A[i]:
    cnt += 2
  else:
    cnt += 1
print(cnt)