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

#define ll long long
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define ps push
#define in insert
#define f first
#define s second
#define nl cout<<"\n"
#define ca(v) for(auto i:v) cout<<i<<" ";
#define cbit(x) __builtin_popcount(x)
#define gcd(a, b) __gcd(a, b)
#define lcm(a, b) (a*b/gcd(a, b))
int xm[4] = {-1, 1, 0, 0};
int ym[4] = {0, 0, -1, 1};
const int MOD = 1e9 + 7;
const int MAXN = 5e5 + 5;
const ll POW = 9973;

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    string s;cin>>s;
    string A,B;
    bool flag = false;
    for(int i=0;i<s.size();i++) {
        if (s[i]=='/') {
            flag = true;
            continue;
        }
        if (flag) {
            B+=s[i];
        } else A+=s[i];
    }
    int a = stoi(A);
    int b = stoi(B);

    for (int i=1;i<=2000;i++) {
        // n nodes
        int mn = i-1;
        int mx = (i-1)*i/2;
        if (i%b ==0) {
            int sum = i/b*a;
            if (sum>=mn && sum<=mx) {
                int cur = mx-sum;
                int n = i;
                vector<int> ans(n);
                for (int j=1;j<n;j++) {
                    ans[j] = j-1;
                }
                for (int j=n-1;j>=0;j--) {
                    int cando = j-1;
                    ans[j] = max(0, j-cur-1);
                    cur -= cando;
                    if (cur<=0) {
                        break;
                    }
                }
                cout << i << " " << i-1 << '\n';
                for (int j=1;j<i;j++) {
                    cout << ans[j]+1 << " " << j+1 << '\n';
                }
                return 0;
            }
        }
    }
    cout << "impossible" << endl;
}