const N = 200000;
  c = 0;
  for (let rep = 0; rep < 10; rep++)
  for (n of [30, 100, 300, 1000, 3000]) {
    console.log(n);
    a = [];
    for (let i = -n/2; i < n/2; i++) {
      a[i] = [];
      for (let j = -n/2; j < n/2; j++) {
        a[i][j] = 'B'
      }
    }
    console.time('mew');
    for (let it = 0; it < N; it++) {
      const x = N%(n-10)-n/2+2;
      const y = N%(n-20)-n/2+5;
      c = a[x][y];
    }
    console.timeEnd('mew');
  }
  console.log(c);