Problem:
Score : 400 points

Problem Statement

You have N items and a bag of strength W.
The i-th item has a weight of w_i and a value of v_i.

You will select some of the items and put them in the bag.
Here, the total weight of the selected items needs to be at most W.

Your objective is to maximize the total value of the selected items.

Constraints

1 ≤ N ≤ 100

1 ≤ W ≤ 10^9

1 ≤ w_i ≤ 10^9

For each i = 2,3,...,N, w_1 ≤ w_i ≤ w_1 + 3.

1 ≤ v_i ≤ 10^7

W, each w_i and v_i are integers.

Input

Input is given from Standard Input in the following format:

N W
w_1 v_1
w_2 v_2
:
w_N v_N

Output

Print the maximum possible total value of the selected items.

Sample Input 1

4 6
2 1
3 4
4 10
3 4

Sample Output 1

11

The first and third items should be selected.

Sample Input 2

4 6
2 1
3 7
4 10
3 6

Sample Output 2

13

The second and fourth items should be selected.

Sample Input 3

4 10
1 100
1 100
1 100
1 100

Sample Output 3

400

You can take everything.

Sample Input 4

4 1
10 100
10 100
10 100
10 100

Sample Output 4

0

You can take nothing.

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

/*
cat <<EOF >mistaken-paste
*/

#pragma GCC diagnostic ignored "-Wincompatible-pointer-types"

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <math.h>

#define BIG 2000000007

#define MOD 1000000007
typedef uint64_t ull;
typedef  int64_t sll;

#define N_MAX 1000
#define M_MAX 30

typedef struct {
	int32_t a;
	int32_t b;
} hw;

typedef struct {
	sll a;
	sll b;
} hwll;

typedef struct {
	hwll a;
	hwll b;
} linell;


typedef struct {
	ull s;
	ull t;
	int32_t c;
} struct_a;



const hw vector8[8] = {
	{-1, -1},
	{-1,  0},
	{-1, +1},
	{ 0, -1},
	{ 0, +1},
	{+1, -1},
	{+1,  0},
	{+1, +1}
};

ull n, m;
ull h, w;
ull k;
ull vua, vub, vuc, vud, vue, vuf;
sll vsa, vsb, vsc, vsd, vse, vsf;
long double vra, vrb, vrc;
size_t slen;
size_t tlen;
ull a[N_MAX];
// sll a[N_MAX];
// ull a[N_MAX][N_MAX];
ull wall[M_MAX][N_MAX];
ull b[N_MAX];
// sll b[N_MAX];
// ull b[N_MAX][N_MAX];
// sll b[N_MAX][N_MAX];
// ull c[N_MAX];
// char s[N_MAX + 1];
// char t[N_MAX + 1];
// char s[N_MAX][M_MAX + 1];

ull dp[N_MAX];
// sll dp[N_MAX];
// bool dp[N_MAX];
// ull dq[N_MAX];
// ull dp[N_MAX + 1][M_MAX + 1];
ull dq[M_MAX][N_MAX];
// hwll dp[N_MAX + 1][N_MAX + 1];
// struct_a dp[N_MAX + 1][N_MAX + 1];

// hw arr[N_MAX];
// hwll arr[N_MAX * 2];
// hw brr[M_MAX];
// linell arr[N_MAX];

// ull bitdp[1 << N_MAX];

// ull digitdp[10001][   2][  100];
//            pos  less  carry


// struct_a arr[N_MAX * 2];
// struct_b brr[N_MAX * 2];

void swap_adj (ull *a, ull *b) {
	if (*a != *b) {
		ull tmp = *b;
		*b = *a;
		*a = tmp;
	}
	return;
}

ull divide (ull a, ull b) {
	ull x = MOD - 2;
	ull ans = 1;
	while (x) {
		if (x & 1) ans = (ans * b) % MOD;
		b = (b * b) % MOD;
		x /= 2;
	}
	return (a * ans) % MOD;
}

int32_t digits (ull x) {
	int32_t i = 1;
	while (x >= 10) {
		x /= 10;
		i++;
	}
	return i;
}

ull umin (ull x, ull y) {
	return (x < y) ? x : y;
}

ull umax (ull x, ull y) {
	return (x > y) ? x : y;
}

sll smin (sll x, sll y) {
	return (x < y) ? x : y;
}

sll smax (sll x, sll y) {
	return (x > y) ? x : y;
}

ull gcd (ull x, ull y) {
	if (x < y) {
		return gcd(y, x);
	} else if (y == 0) {
		return x;
	} else {
		return gcd(y, x % y);
	}
}

ull bitpow (ull a, ull x, ull modulo) {
	ull result = 1;
	while (x) {
		if (x & 1) {
			result *= a;
			result %= modulo;
		}
		x /= 2;
		a = (a * a) % modulo;
	}
	return result;
}

// int32_t nextroute (int32_t arr[]) {
// 	int32_t i = n - 1;
// 	int32_t j, x;
// 	while (arr[i - 1] > arr[i]) i--;

// 	x = n;
// 	for (j = i; j < n; j++) {
// 		if (arr[j] < arr[i - 1]) continue;
// 		if (x == n || arr[x] > arr[j]) x = j;
// 	}
// 	arr[i - 1] ^= arr[x];
// 	arr[x] ^= arr[i - 1];
// 	arr[i - 1] ^= arr[x];

// 	qsort(&arr[i], n - i, sizeof(int32_t), comp);
// 	return 0;
// }

int32_t targetdig (ull x, int32_t index /* 1-indexed */) {
	// static...?
	int32_t posmax = digits(x);
	if (posmax < index) return -1;
	while (posmax > index) {
		posmax--;
		x /= 10;
	}
	return x % 10;
}

int32_t charcomp (const char left, const char right) {
	if (left < right) {
		return -1;
	} else if (left > right) {
		return +1;
	} else {
		return 0;
	}
}

int32_t pcharcomp (const char *left, const char *right) {
	return charcomp(*left, *right);
}

int32_t pcharrevcomp (const char *left, const char *right) {
	return charcomp(*right, *left);
}

int32_t intcomp (const int32_t left, const int32_t right) {
	if (left < right) {
		return -1;
	} else if (left > right) {
		return +1;
	} else {
		return 0;
	}
}

int32_t pintcomp (const int32_t *left, const int32_t *right) {
	return intcomp(*left, *right);
}

int32_t ullcomp (const ull left, const ull right) {
	if (left < right) {
		return -1;
	} else if (left > right) {
		return +1;
	} else {
		return 0;
	}
}

int32_t pullcomp (const ull *left, const ull *right) {
	return ullcomp(*left, *right);
}

int32_t sllcomp (const sll left, const sll right) {
	if (left < right) {
		return -1;
	} else if (left > right) {
		return +1;
	} else {
		return 0;
	}
}

int32_t psllcomp (const sll *left, const sll *right) {
	return sllcomp(*left, *right);
}

int32_t phwAcomp (const hw *left, const hw *right) {
	return intcomp(left->a, right->a);
}

int32_t phwBcomp (const hw *left, const hw *right) {
	return intcomp(left->b, right->b);
}

int32_t phwABcomp (const hw *left, const hw *right) {
	int32_t x = phwAcomp(left, right);
	if (x) return x;
	return phwBcomp(left, right);
}

int32_t phwllAcomp (const hwll *left, const hwll *right) {
	return sllcomp(left->a, right->a);
}

int32_t phwllBcomp (const hwll *left, const hwll *right) {
	return sllcomp(left->b, right->b);
}

int32_t phwllABcomp (const hwll *left, const hwll *right) {
	int32_t x = phwllAcomp(left, right);
	if (x) return x;
	return phwllBcomp(left, right);
}

int32_t pstrAcomp (const struct_a *left, const struct_a *right) {
	int32_t x;
	if (x = ullcomp(left->t, right->t)) return x;
	if (x = ullcomp(left->s, right->s)) return x;
	if (x = intcomp(left->c, right->c)) return x;
	return 0;
}

int32_t bitlet (char c) {
	return (1 << (c - 'a'));
}

ull ullabs (ull a, ull b) {
	if (a >= b) {
		return a - b;
	} else {
		return b - a;
	}
}

sll sllabs (sll a, sll b) {
	if (a >= b) {
		return a - b;
	} else {
		return b - a;
	}
}

sll nibutanlobo (bool (*func)(sll arg), sll ok, sll ng) {
	while (sllabs(ok, ng) > 1) {
		sll med = (ok + ng) / 2;
		if (func(med)) {
			ok = med;
		} else {
			ng = med;
		}

		// printf("debug: [%lld %lld)\n", ok, ng);
	}

	if (!func(ok)) return ok * 2 - ng;
	return ok;
}

void printquotient (ull left, ull right) {
	const int32_t digits = 20;

	printf("%llu.", left / right);
	left %= right;
	for (int32_t i = 0; i < digits; i++) {
		left *= 10;
		printf("%1d", left / right);
		left %= right;
	}
	puts("");

	return;
}


bool isonedge (hwll x) {
	return (x.a == 0) || (x.a == h) || (x.b == 0) || (x.b == w);
}

ull converttoint (hwll x) {
	if (x.a == 0) {
		return w - x.b; // w ~ 0
	} else if (x.b == 0) {
		return w + x.a; // w ~ h+w
	} else if (x.a == h) {
		return (h + w) + x.b; // h+w ~ h+2w
	} else {
		return (h + w) * 2 - x.a; // (2h+2w) ~ (h+2w)
	}
}

ull solve () {
	sll i, j, ki, l;
	ull result = 0;
	// sll result = 0;
	ull sum = 0;
	// sll sum = 0;
	ull item;
	// qsortの際には"p"ullcompを使う

	// if (k % 2 == 0) {
	// 	for (i = 0; i < n; i++) {
	// 		printf("%llu%c", ((i == 0) ? (k / 2 - 1) : (k / 2)), ((i == n - 1) ? '\n' : ' '));
	// 	}
	// } else {
	// 	//
	// }

	// ull p2, p3, p5;
	// p2 = p3 = p5 = 0;
	// while (n % 2) {
	// 	n /= 2;
	// 	p2++;
	// }
	// while (n % 3) {
	// 	n /= 3;
	// 	p3++;
	// }
	// while (n % 5) {
	// 	n /= 5;
	// 	p5++;
	// }
	// if (n > 1) goto fail;



	for (i = 0; i < n; i++) {
		ull costdiff = b[i] - b[0];
		wall[costdiff][dp[costdiff]] = a[i];
		dp[costdiff]++;
	}

	for (i = 0; i < 4; i++) {
		qsort(wall[i], dp[i], sizeof(ull), pullcomp);
		for (j = 0; j <= dp[i]; j++) {
			dq[i][j] = (j ? dq[i][j - 1] + wall[i][j - 1] : 0);
		}
	}

	for (i = 0; i <= dp[1]; i++) {
		if (i * (b[0] + 1) > k) break;

		for (j = 0; j <= dp[2]; j++) {
			if (i * (b[0] + 1) + j * (b[0] + 2) > k) break;

			for (ki = 0; ki <= dp[3]; ki++) {
				ull cost = i * (b[0] + 1) + j * (b[0] + 2) + ki * (b[0] + 3);
				if (cost > k) break;

				ull value = dq[1][i] + dq[2][j] + dq[3][ki] + dq[0][umin((k - cost) / b[0], dp[0])];
				if (result < value) result = value;
			}
		}
	}

	printf("%llu\n", result);
	// puts(s);

	return 0;

	success:
	puts("YES");
	// puts("Yes");
	// printf("%llu\n", result);
	return 0;

	fail:
	puts("NO");
	// puts("No");
	// puts("0");
	return 1;
}

int32_t main (void) {
	int32_t i, j;
	int32_t x, y;

	// scanf("%llu%llu", &h, &w);
	scanf("%llu%llu", &n, &k);
	// scanf("%llu%llu", &k, &n);
	// scanf("%llu%llu", &vua, &vub, &vuc, &vud);
	// scanf("%s", s);
	// scanf("%s", t);
	// scanf("%lld%lld", &vsa, &vsb);
	// for (i = 0; i < n; i++) {
	// 	scanf("%llu", &a[i]);
	// }

	// for (i = 0; i < h; i++) {
	// 	scanf("%llu", &a[i]);
	// }
	// for (i = 0; i < w; i++) {
	// 	scanf("%llu", &b[i]);
	// }
	for (i = 0; i < n; i++) {
		scanf("%llu%llu", &b[i], &a[i]);
	}
	// for (i = 0; i < h; i++) {
	// 	for (j = 0; j < w; j++) {
	// 		scanf("%llu", &a[i][j]);
	// 	}
	// }

	solve();

	// for (i = 0; i < n; i++) {
	// 	// scanf("%llu%llu", &vua, &vub);
	// 	scanf("%s", s);
	// 	solve();
	// }

	// while (scanf("%llu%llu", &n, &k), n + k) {
	// 	for (i = 0; i < n; i++) {
	// 		scanf("%llu", &a[i]);
	// 	}
	// 	solve();
	// }

	return 0;
}