count common chars

#include <iostream>

int main() {
  using namespace std;

  string s1, s2;
  cin >> s1 >> s2;

  int m1['z' - 'a'] = {0}, m2['z' - 'a'] = {0};
  for (int i = 0; i < s1.size(); i++)
    m1[s1[i] - 'a']++;
  for (int i = 0; i < s2.size(); i++)
    m2[s2[i] - 'a']++;

  for (int i = 0; i < 'z' - 'a'; i++) {
    if (m1[i] > 0 && m2[i] > 0)
      cout << (char)(i + 'a') << " comune" << endl;
  }

  return 0;
}