def Main():
    n=int(input())
    s=input()
    t=input()
    s1=s[::-1]
    ans=0
    ans1=0
    for i in range(n):
        if s[i]!=t[i]:
            ans+=1
        if s1[i]!=t[i]:
            ans1+=1
    
    print(min(ans,ans1))
    
Main()