1 #include<iostream>
2 #include<algorithm>
3 #include<cstring>
4 #include<cstdio>
5 using namespace std;
6 const int maxn=2010;
7 struct node
8 {
9 int a,b;
10 }gua[maxn];
11 int dp[maxn][maxn];
12 int n;
13 bool cmp(node a,node b)
14 {
15 return a.a>b.a;
16 }
17 int main()
18 {
19 cin>>n;
20 for(int i=1;i<=n;i++)
21 {
22 cin>>gua[i].a>>gua[i].b;
23 }
24 sort(gua+1,gua+1+n,cmp);
25 memset(dp,-0x3f,sizeof(dp));
26 dp[0][1]=0;
27 for(int i=1;i<=n;i++)
28 {
29 for(int j=0;j<=n;j++)
30 {
31 dp[i][j]=max(dp[i-1][j],dp[i-1][max(j-gua[i].a,0)+1]+gua[i].b);
32 }
33 }
34 int ans=-999999999;
35 for(int i=0;i<=n;i++)
36 {
37 ans=max(ans,dp[n][i]);
38 }
39 cout<<ans<<endl;
40 return 0;
41 }
