#include "bits/stdc++.h" #define REP(i, n) for(decltype(n) i = 0; i < (n); i++) #define REP2(i, x, n) for(decltype(x) i = (x); i < (n); i++) #define RREP(i, n) for (decltype(n) i = (n) - 1;i >= 0; i--) #define ALL(a) (a).begin(),(a).end() #define SORT(c) sort((c).begin(),(c).end()) #define DESCSORT(c) sort(c.begin(), c.end(), greater()) #define LL long long int #define LD long double #define PI 3.14159265358979 #define _CRT_SECURE_NO_WARNINGS using namespace std; //================================================ int main() { ios::sync_with_stdio(false); cin.tie(0); int N, ans = 0; string S, T; cin >> N >> S >> T; REP(i, N) { if (S[i] != T[i]) { ans++; } } cout << ans << "\n"; return 0; }