#include <bits/stdc++.h>
using namespace std;
inline int two(int n) { return 1 << n; }
inline int test(int n, int b) { return (n >> b) & 1; }
inline void set_bit(int& n, int b) { n |= two(b); }
inline void unset_bit(int& n, int b) { n &= ~two(b); }
inline int last_bit(int n) { return n & (-n); }
inline int ones(int n) {
  int res = 0;
  while (n && ++res) n -= n & (-n);
  return res;
}
const long double PI = 3.1415926535897932384626;
const long long int MAX = 1000000000 + 7;
bool store[30][30];
long long int pos[30][30];
int main() {
  memset(store, 0, sizeof(store));
  long long int n;
  scanf("%lld", &n);
  string a, b;
  cin >> a >> b;
  long long int cnt = 0;
  long long int x, y;
  long long int flag = 0;
  for (long long int i = 0; i < n; i++) {
    if (a[i] != b[i]) {
      store[a[i] - 'a'][b[i] - 'a'] = 1;
      pos[a[i] - 'a'][b[i] - 'a'] = i;
      cnt++;
      if (store[a[i] - 'a'][b[i] - 'a'] and store[b[i] - 'a'][a[i] - 'a'] and
          (!flag)) {
        x = pos[a[i] - 'a'][b[i] - 'a'];
        y = pos[b[i] - 'a'][a[i] - 'a'];
        cnt -= 2;
        flag = 1;
      }
    }
  }
  if (flag) {
    cout << cnt << endl;
    cout << x + 1 << " " << y + 1 << endl;
    return 0;
  }
  long long int flag1 = 0;
  for (long long int i = 0; i <= 26; i++) {
    for (long long int j = 0; j <= 26; j++) {
      for (long long int k = 0; k <= 26; k++) {
        if (i != j) {
          if (store[i][k] and store[k][j]) {
            x = pos[i][k];
            y = pos[k][j];
            cnt -= 1;
            flag1 = 1;
            break;
          }
        }
      }
    }
    if (flag1) break;
  }
  if (flag1) {
    cout << cnt << endl;
    cout << x + 1 << " " << y + 1 << endl;
  } else {
    cout << cnt << endl;
    cout << "-1 -1" << endl;
  }
  return 0;
}
