import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

def sqrt(x):
    ok = 10 ** 18
    ng = 0
    while ok - ng > 1:
        mid = ok + ng >> 1
        if mid * mid >= x:
            ok = mid
        else:
            ng = mid
    return ok
a, b, c = na()
if a < 0:
    a = -a
    b = -b
    c = -c

# p < q を解としたとき floor(a) と ceil(b) を求めたい

d = sqrt(b * b - 4 * a * c)

# print(b, d)
p = (-b - d) // a
q = (-b + d - 1) // a + 1

# print(p, q)
# assert p < q
print(max(0, q - p - 1))