#define MD 998244353

Comb<Mint>h;

ll@t,n[t],m[],o[],a[],r[];
rd((n,m)(t));
rep(i,t)o[i]=n[i]/450;
sortA_index(t,o,m,n,a);

ll b=0,c=0;
Mint z=1;

rep(i,t){
	ll e=n[i]-1;
	ll f=m[i]-1;
	if(f<c){
		z=1;
		c=0;
		b=e;
	}
	while(b<e){
		z=z*2-h.C(b,c);
		++b;
	}
	while(b>e){
		--b;
		z=(z+h.C(b,c))/2;
	}
	while(c<f){
		++c;
		z+=h.C(b,c);
	}
	r[a[i]]=z*(Mint(2)**(b+1)-1);
}
wtLn(r(t));