n,m = map(int, input().split())
s = []

for _ in range(n):
    n_ = int(input())
    t = []
    for _ in range(n_):
        a,b = map(int, input().split())
        t.append([a,b])
    s.append(t)

f = [[0 for _ in range(m+1)] for _ in range(n)]
for i in range(n):
    for j in range(m+1):
        f[i][j] = f[i-1][j]
        for v,w in s[i]:
            if j >= v:
                f[i][j] = max(f[i][j], f[i-1][j-v] + w)
print(f[n-1][m])