#pragma comment(linker, "/STACK:10240000,10240000")

 #include <iostream>

 #include <cstdio>

 #include <algorithm>

 #include <cstdlib>

 #include <cstring>

 #include <map>

 #include <queue>

 #include <deque>

 #include <cmath>

 #include <vector>

 #include <ctime>

 #include <cctype>

 #include <set>

 using namespace std;

 #define mem0(a) memset(a, 0, sizeof(a))

 #define lson l, m, rt << 1

 #define rson m + 1, r, rt << 1 | 1

 #define define_m int m = (l + r) >> 1

 #define rep(a, b) for (int a = 0; a < (b); a++)

 #define rep1(a, b) for (int a = 1; a <= (b); a++)

 #define all(a) (a).begin(), (a).end()

 #define lowbit(x) ((x) & (-(x)))

 #define constructInt4(name, a, b, c, d) name(int a = 0, int b = 0, int c = 0, int d = 0): a(a), b(b), c(c), d(d) {}

 #define constructInt3(name, a, b, c) name(int a = 0, int b = 0, int c = 0): a(a), b(b), c(c) {}

 #define constructInt2(name, a, b) name(int a = 0, int b = 0): a(a), b(b) {}

 #define pc(a) putchar(a)

 #define ps(a) printf("%s", a)

 #define pd(a) printf("%d", a)

 #define sd(a) scanf("%d", &a)

 typedef double db;

 typedef long long LL;

 typedef pair<int, int> pii;

 typedef multiset<int> msi;

 typedef set<int> si;

 typedef vector<int> vi;

 typedef map<int, int> mii;

 const int dx[] = {, , , -, , , -, -};

 const int dy[] = {, , -, , -, , , -};

 const int maxn = 1e5 + ;

 const int maxm = 1e5 + ;

 const int maxv = 1e7 + ;

 const int max_val = 1e6 + ;

 const int MD = 1e9 +;

 const int INF = 1e9 + ;

 const double PI = acos(-1.0);

 const double eps = 1e-;

 template<class T> T gcd(T a, T b) { return b == ? a : gcd(b, a % b); }

 int f[], a[], b[];

 int main() {

     //freopen("in.txt", "r", stdin);

     int n, l;

     while (cin >> n >> l) {

         rep(i, n) {

             sd(a[i]);

             sd(b[i]);

         }

         int maxt = ;

         mem0(f);

         rep(i, n) {

             rep(j, maxt) {

                 f[j + a[i]] = max(f[j + a[i]], f[j] + j * b[i]);

             }

         }

         int ans;

         rep(i, maxt * ) {

             if (f[i] >= l) {

                 ans = i;

                 break;

             }

         }

         cout << ans << endl;

     }

     return ;

 }