include[HTML_REMOVED]

include[HTML_REMOVED]

using namespace std;
const int N=1010;
char a[N],b[N];
int n;

int main()
{
cin>>n;
for(int i=0;i[HTML_REMOVED]>a[i];
for(int i=0;i[HTML_REMOVED]>b[i];

int cnt=0;
for(int i=0;i<n;i++)
{
    int j=i;

    if(a[j]!=b[j])
    {
        while(a[j]!=b[j]) j++;
        cnt++;
    }
    i=j;
}


cout<<cnt;
return 0;

}