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

#define ll long long

int A, B;

int main()
{
	vector<int> h(1010101), V(1010101);
	scanf("%d/%d", &A, &B);
	for(ll a=A, b=B; b<=1000000; a+=A, b+=B)
	{
		ll N = b;
		if (N-1 <= a && a <= N*(N-1)/2)
		{
			// a개를 분배하자
			for(int i=2; i<=N; i++)
				h[i] = 1;
			a -= N-1;

			for(int i=2; i<=N; i++)
			{
				ll cnt = min(a, (ll)i-1 - h[i]);
				a -= cnt;
				h[i] += cnt;
			}

			vector<pair<int, int> > e;
			V[0] = 1;
			for(int i=2; i<=N; i++)
			{
				e.push_back({V[h[i]-1], i});
				if (V[h[i]] == 0) V[h[i]] = i;
			}

			cout << N << " " << e.size() << "\n";
			for(auto [x,y] : e)
				cout << x << " " << y << "\n";

			return 0;
		}
	}
	printf("impossible\n");
	return 0;
}