#include <bits/stdc++.h>

const int N = 1e6 + 5;
int a, b, n;

int sd;
int tax[N];

int main() {
  scanf("%d/%d", &a, &b);
  int g = std::__gcd(a, b);
  a /= g, b /= g;

  bool flag = false;
  for (int k = 1; b * k <= 1000000; k++) {
    n = b * k;
    if (1ll * (n - 1) * b > 1ll * a * n) continue;
    if (1ll * (n - 1) * b < 2ll * a) continue;
    a *= k, flag = true;
    break;
  }

  if (!flag) {
    puts("impossible");
    return 0;
  }

  // set the max;
  for (int i = 0; i < n; i++)
    tax[i] = 1, sd += i;
  
  int max_at = n - 1;
  while (sd > a) {
    if (max_at - 1 < sd - a) {
      tax[max_at] -= 1;
      tax[1] += 1;
      sd -= max_at - 1;
      if (tax[max_at] == 0) --max_at;
      continue;
    }

    tax[max_at] -= 1;
    tax[max_at - (sd - a)] += 1;
    if (tax[max_at] == 0) --max_at;
    sd = a;
  }

  printf("%d %d\n", n, n - 1);
  int cur = 1, last = 1;
  for (int i = 1; i <= max_at; i++) {
    while (tax[i]--)
      printf("%d %d\n", last, ++cur);
    last = cur;
  }
  return 0;
}