[n,v]=map(int, input().split())
groups=[[] for i in range(n)]
cnts=[]
for i in range(n):
    cnt=int(input())
    cnts.append(cnt)
    for _ in range(cnt):
        groups[i].append([int(x) for x in input().split()])

memory=[0]*(1+v)
for i1 in range(n):
    for i2 in range(v,-1,-1):
        tmp=memory[i2]
        for i3 in range(cnts[i1]):
            if i2>=groups[i1][i3][0]:
                tmp=max(tmp,memory[i2-groups[i1][i3][0]]+groups[i1][i3][1])
        memory[i2]=tmp
print(memory[-1])