#import<bits/stdc++.h>
using z=long;z m=998244353,l,r;std::map<z,z>q;z y(z x){return x<2?x*2:q[x]?q[x]:q[x]=(y(x/2)+(y(++x/=2)+y(x-1))*(m/2+1)+x)%m;}main(){std::cin>>l>>r;std::cout<<(y(r)-y(--l)+m)%m;}

机房一群人闲得慌