import java.util.*;

public class Email {

public int solution(String[] L) {

// write your code in Java SE 8

if(L == null || L.length <= 1) {

return 0;

}

HashMap<String, Integer> map = new HashMap<>();

for(String s : L) {

s = clear(s);

map.put(s, map.getOrDefault(s, 0) + 1);

}

int res = 0;

for(Map.Entry<String, Integer> entry : map.entrySet()) {

if(entry.getValue() >= 2) {

res++;

}

}

return res;

}

private String clear(String s) {

String[] a = s.split("@");

int index = a[0].indexOf("+");

if(index != -1) {

a[0] = a[0].substring(0, index);

}

StringBuilder sb = new StringBuilder();

for(int i = 0; i < a[0].length(); i++) {

if(a[0].charAt(i) != '.') {

sb.append(a[0].charAt(i));

}

}

a[0] = sb.toString() + a[1];

return a[0];

}

}