#include <bits/stdc++.h>   using namespace std;   int n, d;   string s, t;   map<pair<char, char>, vector<int> > M;   map<char, vector<int> > N;   int main() {     ios_base::sync_with_stdio(false);     cin >> n >> s >> t;     d = 0;     for (int i = 0; i < n; ++i) {       if (s[i] != t[i]) {         M[make_pair(s[i], t[i])].push_back(i + 1);         N[s[i]].push_back(i + 1);         ++d;       }     }     for (int i = 0; i < n; ++i) {       if (s[i] != t[i]) {         map<pair<char, char>, vector<int> >::iterator it =             M.find(make_pair(t[i], s[i]));         if (it != M.end()) {           cout << d - 2 << endl;           cout << i + 1 <<     << it->second.back() << endl;           return 0;         }       }     }     for (int i = 0; i < n; ++i) {       if (s[i] != t[i]) {         if (N.find(t[i]) != N.end()) {           cout << d - 1 << endl;           cout << i + 1 <<     << N[t[i]].back() << endl;           return 0;         }       }     }     cout << d << endl;     cout <<  -1 -1  << endl;     return 0;   }   