#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
// your code goes here
ll n;
cin>>n;
string s,s2;
cin>>s>>s2;
ll k=0;
int o=0;
for(ll i=0;i<s.size();i++){
int l = s[i] -'0';
int m = s2[i]-'0';
int p = abs(l-m);
o = 10-abs(l-m);
if(p<o) k+=p;
else k+=o;
}
cout<<k;
return 0;
}
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