package effect.java.annotation;

import java.util.HashSet;

import java.util.Set;

public class Bigram {

private final char first;

private final char second;

public Bigram(char first, char second) {

this.first = first;

this.second = second;

}

// public boolean equals(Bigram b) {

// return b.first == first && b.second == second;

// }

@Override

public boolean equals(Object o) {

if (!(o instanceof Bigram)) {

return false;

}

Bigram b = (Bigram) o;

return b.first == first && b.second == second;

}

public int hashCode() {

return 31 * first + second;

}

public static void main(String[] args) {

Set<Bigram> s = new HashSet<>();

for (int i =0; i <10; i++) {

for (char ch = 'a'; ch<='z'; ch++) {

s.add(new Bigram(ch,ch));

}

}

System.out.print(s.size());

}

}