[백준] 4299번 : AFC 윔블던 - C++

https://www.acmicpc.net/problem/4299

#include <iostream>

using namespace std;

int main() {
    int a,b;
    cin>>a>>b;
    if((a+b)%2==1||a<b) cout<<-1;
    else{
        int n=(a+b)/2;
        int m=a-n;
        cout<<n<<" "<<m;
    }
}