#include "bits/stdc++.h"
#include "ext/pb_ds/assoc_container.hpp"
#include "ext/pb_ds/tree_policy.hpp"
//@etohari
using namespace std;
using namespace __gnu_pbds;

#define my_wife "She belongs to another guy"
#define bit(mask,i) ((mask >> i)&1)
#define cntbit(mask) __builtin_popcountll(mask)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define uniquev(v) sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define sz(s) (int32_t)s.size()
#define __lcm(a,b) ((int64_t)a / __gcd(a, b) * b)
#define rand(l, r) uniform_int_distribution < int64_t > (l, r)(rng)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define ordered_set tree < int32_t, null_type, less < int32_t >, rb_tree_tag,tree_order_statistics_node_update >

void etohari();
void init(){};

signed main() {
        cin.tie(NULL)->sync_with_stdio(false);
        // https://www.facebook.com/hai290605
        constexpr bool MULTITEST = 0;
        // https://codeforces.com/profile/I_Will_Marry_Ngoc
        init();
        int32_t test = 1;
        if (MULTITEST) cin >> test;
        for (int32_t i_test = 1; i_test <= test; i_test ++){
                etohari();
                cout << "\n";
        }
        return (0 ^ 0);
}

template < class T > bool minimum(T& a, T& b) { return b < a ? a = b, 1 : 0; }
template < class T > bool maximum(T& a, T& b) { return a < b ? a = b, 1 : 0; }

constexpr int32_t MAXN = 1e3 + 10;
constexpr int32_t MAXM = 1e6 + 10; 
constexpr int32_t MOD = 1e9 + 7;
constexpr int32_t INF = 0x3f3f3f3f;
constexpr long double PI = 3.14159265358979323846;

constexpr int16_t DR[] = { };
constexpr int16_t DC[] = { };

bool check(int n, int64_t s){
        int64_t minn = n - 1;
        int64_t maxx = n * (n - 1) / 2;
        if (s < minn || s > maxx) return 0;
        cout << n << " " << n - 1 << "\n";
        s -= n - 1;
        int len = 0;
        for (int i = 2; i <= n; i ++){
                if (s == 0){
                        cout << 1 << " " << i << "\n";
                }else {
                        if (len <= s){
                                cout << len + 1 << " " << i << "\n";
                                s -= len;
                                len ++;
                        }else {
                                cout << s << " " << i << "\n";
                                s = 0;
                        }
                }
        }
        return 1;
}

void etohari(){ 
        int a, b;
        char x;
        cin >> a >> x >> b;
        for (int i = 1; i * b <= 1000000; i ++){
                if (check(b * i, i * a))return ;
        }        
        
        cout << "impossible";
}