#include <bits/stdc++.h>
#define ll long long
#define db double
#define cr char
#define scd(x) scanf("%d",&x)
#define prd(x) printf("%d",x)
#define prl() printf("\n")
#define prsp() printf(" ")
#define rep(i,x,y) for(int i=x;i<=y;i++)
using namespace std;
ll n,n1,n2,v,x,y,yu1[30100],yu2[30100],f[60100],l1[60100],l2[60100];
int main(){
    cin>>n>>v;
    for(int i=1;i<=n;i++){
        cin>>x>>y;
        if(x==1) yu1[++n1]=y;
        else yu2[++n2]=y;
    }
    sort(yu1+1,yu1+n1+1);
    sort(yu2+1,yu2+n2+1);
    l1[1]=n1;
    l2[0]=l2[1]=n2;
    f[1]=yu1[n1];
    l1[1]--;
    for(int i=2;i<=v;i++){
        if(f[i-2]+yu2[l2[i-2]]>=f[i-1]+yu1[l1[i-1]]){
            l2[i]=l2[i-2]-1;
            l1[i]=l1[i-1];
            f[i]=f[i-2]+yu2[l2[i-2]];
        }
        else{
            l2[i]=l2[i-2];
            l1[i]=l1[i-1]-1;
            f[i]=f[i-1]+yu1[l1[i-1]];
        }
    }
    cout<<f[v];
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
#define int long long
int read()
{
	char ch=getchar();
	int x=0,m=1;
	while(!isdigit(ch)){
		if (ch=='-') m=-1;
		ch=getchar();
	}
	while(isdigit(ch)){
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x*m;
}
void write(int x)
{
	if (x<0) putchar('-'),x=-x;
	if (x>=10) write(x/10);
	putchar(x%10+'0');
}
int n=read(),v=read(),mid,ans;
struct Node{
	short x;
	int y;
}a[30010];
bool cmp(Node x,Node y)
{
	return x.x < y.x || (x.y > y.y && x.x == y.x);
}
signed main()
{
	for (int i=1;i<=n;i++){
		a[i].x=read();
		a[i].y=read();
		if (a[i].x==1) mid++;
	}
	sort(a+1,a+1+n,cmp);
	int i=0,j=mid;
	while(i<mid&&i<v) ans+=a[++i].y;
	while(j<n&&i+(j-mid+1<<1)<=v) ans+=a[++j].y;
	while(i>=2&&j<n&&a[i].y+a[i-1].y<=a[j+1].y) ans+=a[++j].y-a[i--].y-a[i--].y;
	if (i<mid&&i+(j-mid<<1)<v) ans+=a[++i].y;
	write(ans); 
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
long i,n,m,s,a,b[30005],o,o1,c[30005],k,j;
bool cmp(long x,long y)
{
	return x>y;
}
void main()
{
	cin>>n>>m;
	for(i=1;i<=n;i++)
	{
		cin>>a;
		if(a>1)cin>>b[++o];
		else cin>>c[++o1];
	}
	sort(b+1,b+o+1,cmp);
	sort(c+1,c+o1+1,cmp);
	i=j=1;
	while(m)
	{
		if(m>1)
		{
			if(b[i]<c[j]+c[j+1])s+=c[j]+c[j+1],j+=2;
			else s+=b[i],i++;
			m-=2;
		}
		else{
			s+=c[j];
			j++;
			m--;
		}
	}cout<<s;
	return;
}