import sys
from math import sqrt, pi, sin
inp = lambda : sys.stdin.readline()[:-1]
mii = lambda x = " ": [*map(int,inp().split(x))]
mfi = lambda x = " ": [*map(float,inp().split(x))]
ii = lambda : int(inp())
for tc in range(ii()):
n, speed, d = mii()
l = [mii() for _ in range(n)]
ans = 0
for dis, val in l:
left_day = dis // speed + int(dis % speed > 0)
if left_day <= d:
ans += val
print(f"Data Set {tc+1}:")
print(ans)
print()