#include <bits/stdc++.h>
using namespace std;

int main() {
	int arr[]= {1, -2, 1, 0, 5};
	int n=sizeof(arr)/sizeof(arr[0]);
	int x=0;
	bool flag=false;
	unordered_set<int> mp;
	for(int j=0;j<n;j++)
	{
		int diff=x-arr[j];
		if(mp.find(diff)!=mp.end()){
			flag=true;
			cout<<"true";
			break;
		}
		mp.insert(arr[j]);
	}
	if(flag==false)
		cout<<"false";
	return 0;
}