N, V, C = map(int,input().split())
dp = [[0] * (N+1)] * (V+1)
for x in range(N):
	v, w = int(input())
	if v > V:
		continue
	for y in range(v, V+1):
		dp[y][x+1] = max(dp[y][x], dp[y-v][x] + w+c)
print(dp[-1][-1])