#pragma GCC optimize("Ofast") #pragma GCC target("avx2") #define rd() ({long _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;}) #define wt(v) {ulong _z=v;do*--wp=_z%10+48;while(_z/=10);} #define rrep3(v,s,e) for(long v=e;--v>=s;) typedef unsigned long ulong; #define MD 998244353 #define M 200002 int fac[M],ifac[M]; int inverse(int a){ int b=MD; int u=1; int v=0; int s,t; while(b){ t=a/b; s=b; b=a-t*b; a=s; s=v; v=u-t*v; u=s; } if(u<0){ u+=MD; } return u; } void mkfac(){ long x=1; fac[0]=x; for(long i=1;i