import math def count_combinations(n, m): if m < n or m > 5 * n: return 0 numerator_zmin = m - 2 * n denominator_zmin = 3 zmin_float = numerator_zmin / denominator_zmin zmin_ceil = math.ceil(zmin_float) z_min = max(zmin_ceil, 0) numerator_zmax = m - n denominator_zmax = 4 zmax_float = numerator_zmax / denominator_zmax z_max = math.floor(zmax_float) if z_min > z_max: return 0 return z_max - z_min + 1 T = int(input()) for _ in range(T): n, m = map(int, input().split()) print(count_combinations(n, m))