#include <cstdio> #include <cstring> #include <iostream> #include <string> #include <cmath> #include <bitset> #include <vector> #include <map> #include <set> #include <queue> #include <deque> #include <algorithm> #include <complex> #include <unordered_map> #include <unordered_set> #include <random> #include <cassert> #include <fstream> #include <utility> #include <functional> #include <time.h> #include <stack> #include <array> #include <list> #include <atcoder/all> #define popcount __builtin_popcount using namespace std; using namespace atcoder; typedef long long ll; typedef pair<int, int> P; using mint=modint998244353; mint f[2000010], invf[2000010]; void fac(int n){ f[0]=1; for(ll i=1; i<=n; i++) f[i]=f[i-1]*i; invf[n]=f[n].inv(); for(ll i=n-1; i>=0; i--) invf[i]=invf[i+1]*(i+1); } mint comb(int x, int y){ if(!(0<=y && y<=x)) return 0; return f[x]*invf[y]*invf[x-y]; } int main() { int a, b; cin>>a>>b; ll n; cin>>n; if(a==b || a==0){ cout<<0<<endl; return 0; } int g=gcd(2*a*b, b*b-a*a); int s=2*a*b/g, t=(b*b-a*a)/g; int x=s*a+t*b, y=s*b; mint ans=mint(n-x)*mint(n-y); ans*=8; cout<<ans.val()<<endl; return 0; }