http://www.hsin.hr/honi/arhiva/2008_2009/kolo4_zadaci.pdf

trezor.cpp

#include <bits/stdc++.h>

using namespace std;

typedef long long llint;

int A, B, L;

llint f(int dy)
{
	if (dy == 0)
		return 1;
	
	llint sol = 0;	
	vector<int> divs;
	
	if (dy % 2 == 0)
	{
		divs.push_back(2);
		while (dy % 2 == 0)
			dy /= 2;
	}
	
	for (int d = 3; d <= dy; d += 2)
	{
		if (dy % d == 0)
		{
			divs.push_back(d);
			while (dy % d == 0)
				dy /= d;
		}
	}
	
	for (int bit = 0; bit < (1<<divs.size()); ++bit)
	{
		int x = 1, sgn = 1;
		for (int i = 0; i < divs.size(); ++i) if (bit & 1<<i)
		{
			x *= divs[i];
			sgn = -sgn;
		}
		sol += sgn * L / x;
	}
	
	return sol;
}

llint s1(int y)
{
	return f(y + A);
}

llint s2(int y)
{
	return f(B - y);
}

llint s12(int y)
{
	return f((y + A) * (B - y));
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int a, b, c;
	llint ns = 0, s = 0, ss = 0;
	
	cin>>A>>B>>L;
	
	for (int y = -A; y <= B; ++y)
	{
		a = s1(y);
		b = s2(y);
		c = s12(y);
		
		ss += c;
		s += a + b - 2 * c;
		ns += L - a - b + c;
	}
	
	cout<<ns<<endl<<s<<endl<<ss<<endl;
}