#include <bits/stdc++.h>

using namespace std;

long long solve(long long N, long long R) {

    for (int k = 1;; ++k) {
        long long start = k * k - k + 1;
        long long margin = k - 1;

        bool isGood = true;
        for (int i = 1; i < N; ++i) {
            long long here = start + R * i;

            int floorSqrt = (int)sqrt(here);
            int ceilSqrt  = floorSqrt + 1;
            if (floorSqrt * floorSqrt == here) {
                ceilSqrt = floorSqrt;
            }

            long long upperBound = ceilSqrt * ceilSqrt;
            long long lowerBound = upperBound - ceilSqrt + 1;

            if (here + margin < lowerBound) {
                isGood = false;
                break;
            }

            if (here < lowerBound) {
                start += (lowerBound - here);
                margin -= (lowerBound - here);
            } else if (here + margin > upperBound) {
                margin -= here + margin - upperBound;
            }
        }
        if (isGood) {
            return start;
        }
    }

}

int main() {

    ifstream in("progresie.in");
    ofstream out("progresie.out");

    FILE* readFile = fopen("progresie.in", "r");
    FILE* writeFile = fopen("progresie.out", "w");

    int T = 0;
    fscanf(readFile, "%d", &T);
    int N, R;
    for (int i = 0; i < T; ++i) {
        fscanf(readFile, "%d", &N);
        fscanf(readFile, "%d", &R);
        fprintf(writeFile, "%lld\n", solve(N, R));
    }

    return 0;
}