#include<bits/stdc++.h>
#define rep(x,y,z) for(int x=y;x<=z;x++)
#define drep(x,y,z) for(int x=y;x>=z;x--)
#define ull unsigned long long
#define ll long long
using namespace std;
inline ll read()
{
	ll x=0;bool flag=1;char ch=getchar();
	while(ch<'0'||ch>'9') {if(ch=='-')flag=0;ch=getchar();}
	while(ch>='0'&&ch<='9') {x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}
	if(flag) return x;
	return ~(x-1);
} 
inline void write(int x)
{
	if(x<0) {x=~(x-1);putchar('-');}
	if(x>9) write(x/10);
	putchar(x%10+'0');
}
//////////////////////////////////////////
const ll mod=9;
int nc;
int k[10];
int main()
{
    freopen("xiaokai.in","r",stdin);
	freopen("xiaokai.out","w",stdout);
	rep(i,1,8) k[i]=k[i-1]+i;
    nc=read();
    ll s1,s2;
    rep(i,1,nc)
    {
    	s1=(read()-1)%mod;
    	s2=read()%mod;
    	write(abs((k[s2]-k[s1]%mod+mod)%mod));
    	putchar(10);
	}
    return 0;
}