import sys
mp = map(int, sys.stdin.read().split())

# calc sum_{i=0}^{n-1} floor((ai + b) / m)
def floor_sum_unsigned(n: int, m: int, a: int, b: int) -> int:
	assert n >= 0 and m > 0 and a >= 0 and b >= 0
	ans = 0
	while True:
		if a >= m:
			q, a = divmod(a, m)
			ans += (n * (n - 1) >> 1) * q
		if b >= m:
			q, b = divmod(b, m)
			ans += n * q
		y_max = a * n + b
		if y_max < m: return ans
		n, b = divmod(y_max, m)
		m, a = a, m

def solve(n: int, d: int, m: int, s: int) -> int:
	assert n >= 0 and d > 0 and m >= 0 and s >= 0
	pow2s, dm = 1 << s, d * m
	if pow2s != dm:
		n = min(n, d * pow2s // abs(dm - pow2s))
		n -= abs(floor_sum_unsigned(n + 1, pow2s, m, 0) - floor_sum_unsigned(n + 1, d, 1, 0))
	return n

for _ in range(next(mp)):
	n, d, m, s = next(mp), next(mp), next(mp), next(mp)
	print(solve(n, d, m, s))