package main

type TwoSum struct {
	book map[int]int
}

/** Initialize your data structure here. */
func Constructor() TwoSum {
	return TwoSum{
		make(map[int]int),
	}
}

/** Add the number to an internal data structure.. */
func (this *TwoSum) Add(number int) {
	this.book[number]++
}

/** Find if there exists any pair of numbers which sum is equal to the value. */
func (this *TwoSum) Find(value int) bool {
	for key := range this.book {
		if times, ok := this.book[value-key]; ok {
			if value-key == key && times >= 2 {
				return true
			} else if value-key != key {
				return true
			}
		}
	}
	return false
}