import sys

def dist(A, B):
    return ((A[0]-B[0])**2 + (A[1]-B[1])**2) ** 0.5

n, m = map(int, input().split())
l = float(input())

goal = (n, m)

at = (0, 0)
far = 0
ans = []

def get_pt(d, dest):
    mid = (at[0] + goal[0]) / 2, (at[1] + goal[1]) / 2
    vec = (dest[0] - mid[0]), (dest[1] - mid[1])
    l = dist((0, 0), vec)
    vec = vec[0]/l, vec[1]/l
    return mid[0] + d * vec[0], mid[1] + d * vec[1]

def finish_off(dest):
    lo, hi = 0, n + m
    for i in range(100):
        mid = (lo+hi) / 2
        pt = get_pt(mid, dest)
        if far + dist(at, pt) + dist(pt, goal) <= l:
            lo = mid
        else:
            hi = mid
    pt = get_pt(lo, dest)
    ans.append(pt)
    ans.append(goal)

def goto(dest):
    if far + dist(at, dest) + dist(dest, goal) <= l:
        ans.append(dest)
        return dest, far + dist(at, dest)
    else:
        finish_off(dest)
        output()
        return None, None

def output():
    print(len(ans))
    for p in ans:
        print(*p)
    sys.exit(0)

for x in range(n+1):
    if at is not None:
        at, far = goto((x, 0))
    if at is not None:
        at, far = goto((x, m))
output()