#include <fstream>
#include <vector>
using namespace std;

constexpr int inf = (1<<30);

int main(){
	ifstream in("energii.in");
	ofstream out("energii.out");
	int n = 0, g = 0;
	in >> n >> g;
	vector<int> v(g, inf);
	v[0] = 0;
	int rez = inf;
	for(int i = 0, e = 0, c = 0; i < n; ++i){
		in >> e >> c;
		for(int j = g-1; j >= 0 && j >= g-e; --j){
			if(v[j] != inf){
				rez = min(rez, v[j]+c); } }
		for(int j = g-e-1; j >= 0; --j){
			if(v[j] != inf && v[j]+c < v[j+e]){
				v[j+e] = v[j]+c; } } }
	out << rez;
	return 0; }