#define MD 998244353
ll@N,@(l,r)[N],L,R;wt(sum[i,1,N]((L=min(max(l[i],*l),*r+1),R=min(r[i],*r),max(0,L-*l)+(L<=R)*max(0,(2*r[i]-L-R)*(R-L+1)/2)/Mint(r[i]-l[i]+1)))/(*r-*l+1)+1);