// 河南省实验中学 高中 21级 关天泽

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define re register
#define int ll

const int N = 0x3f3f3f;
using namespace std;

inline int read(){
    int ans=0,sgn=1;
    char ch=getchar();
    while(!isdigit(ch)){
   	if (ch=='-')sgn=-1;
   	ch=getchar();
    }
    while(isdigit(ch))ans=(ans<<3)+(ans<<1)+(ch^48),ch=getchar();    
    return ans*sgn;
}

int a, b, m, q;

signed main(){
	freopen("xiaokai.in", "r", stdin);
	freopen("xiaokai.out", "w", stdout);
	q = read();
	while (q--){
		m = 0;
		a = read();
		b = read();
		b %= 9;
		a %= 9; 
		if (b < a) b += 9; 
		for (int i = a; i <= b; i++) m += i;
		m %= 9;
		printf("%d\n", m);
	}
	return 0;
}