#include <iostream>
using namespace std;

class Record
{
public:
    Record(int playCount, int winCount)
        : mPlayCount(playCount)
        , mWinCount(winCount)
    {
    }

    int NeedWinGameForOnePercent()
    {
        double playCount = static_cast<double>(mPlayCount);
        double winCount = static_cast<double>(mWinCount);
        double winRate = winCount / playCount * 100;
        double needRate = 1 - (winRate - static_cast<int>(winRate));
        double needMoreGame = ((winRate + needRate) * playCount - 100 * winCount) / (100 - winRate - needRate);

        int game = Ceil(needMoreGame);

        if (0 < game && game <= 2000000000)
        {
            return game;
        }
        else
        {
            return -1;
        }
    }

private:
    int Ceil(double value)
    {
        if (value > static_cast<int>(value))
        {
            return static_cast<int>(value)+1;
        }
        else
        {
            return static_cast<int>(value);
        }
    }

private:
    int mPlayCount;
    int mWinCount;
};


int main(int argc, char* argv[])
{
    int numOfCase = 0;
    cin >> numOfCase;

    for (int i = 0; i != numOfCase; ++i)
    {
        int playCount;
        cin >> playCount;

        int winCount;
        cin >> winCount;

        Record record(playCount, winCount);
        cout << record.NeedWinGameForOnePercent() << endl;
    }

    return 0;
}

#include <iostream>
using namespace std;

const int MIN_CONT_WIN_COUNT = 1;
const int MAX_CONT_WIN_COUNT = 2000000000;

double gTotalCount = 0.0;
double gWinCount = 0.0;
int gContWinCount = 0;

void NeedGameForOnePercent(unsigned int min, unsigned int max)
{
  if (min <= max)
  {
    unsigned int count = (min + max) / 2;

    if (static_cast<unsigned int>(gWinCount / gTotalCount * 100) <
        static_cast<unsigned int>((gWinCount + count) / (gTotalCount + count) * 100))
    {
      gContWinCount = count;
      return NeedGameForOnePercent(min, count - 1);
    }
    else
    {
      return NeedGameForOnePercent(count + 1, max);
    }
  }
}

int main(int argc, char* argv[])
{
  int numOfGame = 0;
  cin >> numOfGame;

  for (int i = 0; i != numOfGame; ++i)
  {
    cin >> gTotalCount >> gWinCount;
    NeedGameForOnePercent(MIN_CONT_WIN_COUNT, MAX_CONT_WIN_COUNT);

    if (!gContWinCount)
    {
      cout << -1 << endl;
    }
    else
    {
      cout << gContWinCount << endl;
    }

    gContWinCount = 0;
  }
  return 0;
}