/*

     贪心水题：累加到目标数字的距离，两头找取最小值

 */

 #include <cstdio>

 #include <iostream>

 #include <algorithm>

 #include <cstring>

 using namespace std;

 const int MAXN = 1e3 + ;

 const int INF = 0x3f3f3f3f;

 char s[MAXN], t[MAXN];

 int main(void)        //Codeforces Round #301 (Div. 2) A. Combination Lock

 {

     //freopen ("A.in", "r", stdin);

     int n;

     while (scanf ("%d", &n) == )

     {

         scanf ("%s", &s);

         getchar ();

         scanf ("%s", &t);

         int ans = ;

         for (int i=; i<n; ++i)

         {

             int tmp = abs (t[i]-s[i]);

             ans += min (tmp,  - tmp);

         }

         printf ("%d\n", ans);

     }

     return ;

 }