#!/usr/bin/env python3
from fractions import Fraction

a, b = map(int, input().split())
c, d = map(int, input().split())
target = Fraction(c,c+d)
split = Fraction(a,a+b)

done = {Fraction(1): -1, Fraction(0): -2}

solution = [None]

def solve(root, target):
    assert len(solution) == root+1
    # Are we done:
    if target in done:
        solution[root] = [done[target], done[target]]
        return
    
    # Find the minimal remaining denominator
    bestval = None
    bestmove = None # (None, id) or (id, None)
    for v, id in done.items():
        # try on the left
        # target = split * v + (1-split)*t2
        t2 = (target - v*split)/(1-split)
        if t2 >= 0 and t2 <= 1 and (bestval is None or t2.denominator < bestval.denominator):
            bestval = t2
            bestmove = [id, None]

        # try on the right
        # target = split * t2 + (1-split)*v
        t2 = (target - v*(1-split))/split
        if t2 >= 0 and t2 <= 1 and (bestval is None or t2.denominator < bestval.denominator):
            bestval = t2
            bestmove = [None, id]

    done[target] = root
    for i in range(2):
        if bestmove[i] is None:
            bestmove[i] = root+1
    solution[root] = bestmove
    solution.append(None)
    solve(root+1, bestval)


solve(0, target)

print(len(solution))
for l, r in solution: print(l, r)