#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 rep3(v,s,e) for(typeof(e) v=s;v<e;++v)
#define MD 998244353

typedef unsigned long ulong;

int main(){
	rd_init();
	long n=rd();
	long a=rd()!=rd();
	ulong f=1;
	rep3(i,1,n-1){
		f=f*i%MD;
	}
	wt1((a+(n-1)*(n-2))%MD*f%MD);
	_exit(0);
}