#include <iostream>
using namespace std;
#define maxn 101
#define maxm 56001
#define infn (int)5E3
#define inf 0x7fffffff
int n;
int r;
int mina = inf;
int w[maxn];
int v[maxn];
int dp[maxm];
int main(){
	cin >> n >> r;
	for(int i = 1; i <= n; ++ i) { cin >> w[i] >> v[i]; }
	for(int i = 1; i <= r + infn; ++ i) { dp[i] = inf; }
	for(int i = 1; i <= n; ++ i) {
		for(int j = w[i]; j <= r + infn; ++ j) {
			dp[j] = min(dp[j], dp[j - w[i]] + v[i]);
		}
	}
	for(int i = r; i <= r + infn; ++ i) { mina = min(mina, dp[i]); }
	cout << mina << '\n';
}