#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
 
int main() {
	int a, b; 
	vector<int> Alist, Blist; 
 
	while (cin >> a >> b) {
       Alist.insert(Alist.end(), a);
       Blist.insert(Blist.end(), b);
    }
 
    for (int i = 0; i < Alist.size(); i++) {
        int g = Alist[i];
        int h = Blist[i];
        if (h>=g)
            for (int y = i+1; y < Blist.size() && Alist[y]<=h; ) {  // start with next, stop if over target
                if (Alist[y] == h && Blist[y] == g) { 
                    Alist.erase(Alist.begin() + y);
                    Blist.erase(Blist.begin() + y);
                    cout << "found "<<h<<" "<<g<<endl; 
                }
                else y++; // move to next only if current one was not erased
            }
    }
 
	return 0;
}

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1     6
1     4
2     4
2     7
2     5
2     3
3     9
3     2
3     5
4     1
4     6
5     3
5     2
5     8
5     9
6     4
6     1
7     2
8     5
8     9
9     3
9     5
9     8