#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=2100000000;
const ll mod=998244353;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}

ll gcd(ll a,ll b){
	while(b!=0) swap(a,b),b%=a;
	return a;
}

//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	

	ll a,b,N;
	cin>>a>>b>>N;
	ll c=gcd(a,b);
	a/=c,b/=c;
	if(a==b){
		cout<<"0\n";
		return 0;
	}
	if(a<b) swap(a,b);
	ll t=(a*a+b*b),s=(a*a-b*b);
	if((a+b)%2==0) t/=2,s/=2;
	ll x=(t+s)*b*c,y=a*t*c;
	/*cout<<x<<" "<<y<<endl;
	cout<<t<<" "<<s<<endl;*/
	if(N<=x&&N<=y) cout<<"0\n";
	else{
		ll ans=1;
		ans*=((N-x)%mod);
		ans%=mod;
		ans*=((N-y)%mod);
		ans%=mod;
		ans*=8ll;
		ans%=mod;
		cout<<ans<<"\n";
	}
}