#include <bits/stdc++.h>
using namespace std;
int main () {
	using ll = long long;
	ll a, b, c;
	cin >> a >> b >> c;
	if (a < 0) {
		a *= -1;
		b *= -1;
		c *= -1;
	}
	ll l, r;
	if (b >= 0) {
		r = b / (2 * a);
		l = r + 1;
		l *= -1;
		r *= -1;
	} else {
		l = (-b) / (2 * a);
		r = l + 1;
	}
	auto clc = [&](ll x) -> ll {
		return a * x * x + b * x + c;
	};
	while (clc(l) < 0) l --;
	while (clc(r) < 0) r ++;
	cout <<r-l-1 << endl;
}