#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() ({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 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; const p2[]={2,4,16,256,65536,301989884,932051910,299560064,169907034,60241440,595200811,819041188,954185916,830057642,679814667,167578608,683753077,918327899,}; int main(){ rd_init(); long n=rd(); ulong z=0; rep(i,n){ z+=(i+2)*rd()<<(rp[-1]==10); z%=MD; } for(int a=0;n;n>>=1,++a){ z=n&1?z*p2[a]%MD:z; } z=z*873463809%MD; wt1(z); _exit(0); }