#include <iostream>
#include <fstream>
#include <string>

using namespace std;

using ull = unsigned long long;

int main(void) {
    ifstream fin("xiaokai.in");
    ofstream fout("xiaokai.out");
    int Q;
    fin >> Q;
    ull l, r;
    ull sum;
    for(int k = 0; k < Q; ++k) {
        fin >> l >> r;
        sum = 0;
        for(ull i = l; i % 9 != 0; ++i)
            sum += i;
        for(ull i = r; i % 9 != 0; --i)
            sum += i;
        fout << sum % 9 << endl;
    }
    return 0;
}