#!/usr/bin/env python3
from collections import Counter


def subseq(s, t):
    i = 0
    for c in s:
        while i < len(t) and t[i] != c:
            i += 1
        if i == len(t):
            return False
        i += 1
    return True


a, b, c, d = input().split()
c, d = int(c), int(d)

n = len(b)
for mask in range(1, 1 << n):
    y = "".join(b[i] for i in range(n) if mask & (1 << i))
    if y[0] == "0":
        continue
    x = str(int(y) * c // d)
    if (
        int(x) * d == int(y) * c
        and subseq(x, a)
        and Counter(a) - Counter(x) == Counter(b) - Counter(y)
    ):
        print("possible")
        print(c, d)
        exit(0)

print("impossible")