Problem:
 Score : 200 points    Problem Statement 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?      Constraints  1 \leq N \leq 100  Each of the strings A, B and C is a string of length N .  Each character in each of the strings A, B and C is a lowercase English letter.         Input Input is given from Standard Input in the following format:  N  A  B  C       Output Print the minimum number of operations required.        Sample Input 1 4
west
east
wait      Sample Output 1 3  In this sample, initially A =  west 、 B =  east 、 C =  wait . We can achieve the objective in the minimum number of operations by performing three operations as follows:   Change the second character in A to a . A is now wast .  Change the first character in B to w . B is now wast .  Change the third character in C to s . C is now wast .        Sample Input 2 9
different
different
different      Sample Output 2 0  If A, B and C are already equal in the beginning, the number of operations required is 0 .       Sample Input 3 7
zenkoku
touitsu
program      Sample Output 3 13

Solution (Python):
N = int(input())
A=input()
B=input()
C=input()

res = 0
for i in range(N):
    st = set([])
    st.add(A[i])
    st.add(B[i])
    st.add(C[i])
    res+=len(st)-1
print(res)

Solution (Python):
N = input()
A = raw_input()
B = raw_input()
C = raw_input()
ans = 0

for i in xrange(N-1, -1, -1):
    S = set([A[i], B[i], C[i]])
    if len(S) == 2:
        ans += 1
    elif len(S) == 3:
        ans += 2

print ans

Solution (Python):

n = int(input())
a = input()
b = input()
c = input()
cnt = 0
for i in range(n):
    if a[i] == b[i] == c[i]:
        pass
    elif a[i] == b[i] or b[i] == c[i] or c[i] == a[i]:
        cnt += 1
    else:
        cnt += 2
print(cnt)

Solution (Python):
n=int(input())
a=input()
b=input()
c=input()

co=0
for i in range(n):
    if a[i]==b[i] and b[i]==c[i]:
        co+=0
    elif a[i]==b[i] or b[i]==c[i] or c[i]==a[i] :
        co+=1
    else :
        co+=2

print(co)

Solution (Python):
def read():
    return int(input())


def readlist():
    return list(map(int, input().split()))


def readmap():
    return map(int, input().split())


N = read()
A = input()
B = input()
C = input()

cnt = 0
for i in range(N):
    if len({A[i], B[i], C[i]}) == 1:
        pass
    elif len({A[i], B[i], C[i]}) == 2:
        cnt += 1
    else:
        cnt += 2

print(cnt)

Solution (Python):
from sys import exit, setrecursionlimit, stderr
from functools import reduce
from itertools import *
from collections import defaultdict, Counter
from bisect import bisect

setrecursionlimit(10**7)

def read():
  return int(input())

def reads():
  return [int(x) for x in input().split()]

N = read()
A = input()
B = input()
C = input()

c = 0

for i in range(N):
  s = {A[i], B[i], C[i]}
  if len(s) == 2:
    c += 1
  elif len(s) == 3:
    c += 2

print(c)

Solution (Python):
N=int(input())
A=input()
B=input()
C=input()
ans=0
for i in range(N):
    S=set([A[i],B[i],C[i]])
    if len(S)==1:
        continue
    elif len(S)==2:
        ans+=1
    else:
        ans+=2
print(ans)

Solution (Python):
N = int(input())
A = input()
B = input()
C = input()

ans = 0
for a, b, c in zip(A, B, C):
    if a == b == c:
        continue
    if a == b or b == c or c == a:
        ans += 1
    else:
        ans += 2
print(ans)

Solution (Python):
n = int(input())
a, b, c = input(), input(), input()
ans = 0
for i in range(n):
    if a[i] == b[i] == c[i]:
        continue
    if a[i] == b[i] or b[i] == c[i] or c[i] == a[i]:
        ans += 1
    else:
        ans += 2
print(ans)