#define mod 998244353

using ll = long long;
void init(int p) {
}
ll bpow (ll a, ll b) {
ll r = 1;
for(;b;b>>=1, a = (a*a)%mod)if(b&1)r=(r*a)%mod;
return r;
}
ll inv(int n){ll nn = n;return bpow(nn, mod - 2);}