import math
t = int(input())
for i in range(t):
s, a, b, c = map(int, input().split())
num = math.floor(s / c) + (math.floor(s / (c * a)) * b)
print(num)
337A - Puzzles | 495A - Digital Counter |
796A - Buying A House | 67A - Partial Teacher |
116A - Tram | 1472B - Fair Division |
1281C - Cut and Paste | 141A - Amusing Joke |
112A - Petya and Strings | 677A - Vanya and Fence |
1621A - Stable Arrangement of Rooks | 472A - Design Tutorial Learn from Math |
1368A - C+= | 450A - Jzzhu and Children |
546A - Soldier and Bananas | 32B - Borze |
1651B - Prove Him Wrong | 381A - Sereja and Dima |
41A - Translation | 1559A - Mocha and Math |
832A - Sasha and Sticks | 292B - Network Topology |
1339A - Filling Diamonds | 910A - The Way to Home |
617A - Elephant | 48A - Rock-paper-scissors |
294A - Shaass and Oskols | 1213A - Chips Moving |
490A - Team Olympiad | 233A - Perfect Permutation |