N, K = map(int, input().split())
PD = [tuple(map(int, input().split())) for _ in range(N)]
PD.sort(key=lambda k: k[0], reverse=True)
dp = [[[-10**18]*2 for _ in range(K+1)] for _ in range(2)]
dp[0][0][0] = 0

for i in range(N):
    Pi, Di = PD[i]
    
    for j in range(K+1):
        dp[(i+1)&1][j][0] = max(dp[i&1][j][0], dp[i&1][j][1]+Di)
        
        if j-Pi>=0:
            dp[(i+1)&1][j][1] = max(dp[i&1][j][1], dp[i&1][j-Pi][0]+Di)
        else:
            dp[(i+1)&1][j][1] = dp[i&1][j][1]

ans = 0

for i in range(K+1):
    for j in range(2):
        ans = max(ans, dp[N&1][i][j])
    
print(ans)