#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------

int N,K;
pair<int,int> P[5050];
int dp[5151][5151][2];


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>K;
	FOR(i,N) {
		cin>>P[i].first>>P[i].second;
	}
	sort(P,P+N);
	reverse(P,P+N);
	FOR(x,5050) FOR(y,5050) dp[x][y][0]=dp[x][y][1]=-1<<30;
	dp[0][K][0]=0;
	
	FOR(i,N) {
		FOR(j,K+1) {
			// no
			dp[i+1][j][0]=max(dp[i+1][j][0],dp[i][j][0]);
			dp[i+1][j][1]=max(dp[i+1][j][1],dp[i][j][1]);
			// buy
			if(j>=P[i].first) dp[i+1][j-P[i].first][1]=max({dp[i+1][j-P[i].first][1],dp[i][j][0]+P[i].second,dp[i][j][1]+P[i].second});
			// free
			dp[i+1][j][0]=max({dp[i+1][j][0],dp[i][j][1]+P[i].second});
		}
	}
	
	int ma=0;
	FOR(i,K+1) ma=max({ma,dp[N][i][0],dp[N][i][1]});
	cout<<ma<<endl;
	
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}