from math import hypot, isclose

(n, m), l = map(int, input().split()), float(input())
res = [(0, 0)]
al, ah = 0, n * m
# Binary search for the in-between point
while not isclose(al, ah):
    a = (al + ah) / 2
    if a + hypot(abs(n - a), m) < l:
        al = a
    else:
        ah = a
res.append((a, 0))
print(str(len(res) + 1) + "\n" + "\n".join(f"{a} {b}" for a, b in (*res, (n, m))))