#pragma GCC optimize("Ofast") #pragma GCC target("avx2") #define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);}) #define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;}) #define wt(v) ({unsigned _z=v;do*--wp=_z%10+48;while(_z/=10);}) #define wt1(v) ({char wbuf[64],*wp=wbuf+sizeof wbuf;wt(v);write(1,wp,wbuf+sizeof wbuf-wp);}) #define rep(v,e) for(typeof(e) v=0;v<e;++v) #define MD 998244353 typedef unsigned long ulong; int inverse(int a){ int b=MD; int u=1; int v=0; while(b){ int q=a/b,t; t=b, b=a-q*b, a=t; t=v, v=u-q*v, u=t; } if(u<0){ u+=MD; } return u; } int main(){ rd_init(); int n=rd(); ulong z=0,b=1; rep(i,n){ b=b*(n-i)%MD; z=(z*(n*2-1-i)+(ulong)rd()*(i+1)%MD*b)%MD; } wt1(z*inverse(b*n%MD)%MD); _exit(0); }