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=list(input())
b=list(input())
c=list(input())

print(a,b,c)

ans=0

for i in range(n):

    s=[a[i],b[i],c[i]]
    buff=set(s)
    ans += len(buff)-1

print(ans)
n=int(input())
a=list(input())
b=list(input())
c=list(input())

ans=0

for i in range(n):

    s=[a[i],b[i],c[i]]
    buff=set(s)
    ans += len(buff)-1

print(ans)