#include <stdio.h>
#include <stdlib.h>

typedef struct {
    int weight; int value;
} Item;

Item* read_items(FILE *f, int items) {

    Item *items_array = malloc(items * sizeof(Item));
    if (items_array == NULL) {
        printf("Error: not enough memory\n");
        exit(1);
    }

    for (int i = 0; i < items; i++) {
        fscanf(f, "%d %d", &items_array[i].weight, &items_array[i].value);
    }

    return items_array;
}

int compare(const void *a, const void *b) {
    Item *itemA = (Item *) a;
    Item *itemB = (Item *) b;
    double ratioA = (double) itemA->value / itemA->weight;
    double ratioB = (double) itemB->value / itemB->weight;
    return (ratioA < ratioB) - (ratioA > ratioB);
}

void sort_items(Item *items_array, int items) {
    qsort(items_array, items, sizeof(Item), compare);
}

void print_items(Item *items_array, int items) {
    for (int i = 0; i < items; i++) {
        printf("%d %d %lf\n", items_array[i].weight, items_array[i].value, (double) items_array[i].value / items_array[i].weight);
    }
}

int pick_items(Item *items_array, int item_count, int max_weight) {
    int weight = 0, total_value = 0, idx = 0;

    while (weight < max_weight && idx < item_count ) {
        if (weight + items_array[idx].weight <= max_weight) {
            weight += items_array[idx].weight;
            total_value += items_array[idx].value;
            idx++;
        } else {
            idx++;
        }
    }

    return total_value;
}


int main() {

    FILE *f = fopen("rucsac.in", "r");
    f == NULL && printf("Error: file not found\n");

    FILE *o = fopen("rucsac.out", "w");
    f == NULL && printf("Error: file not found\n");

    int item_count = 0, max_weight = 0;

    fscanf(f, "%d %d", &item_count, &max_weight);

    Item *items_array = read_items(f, item_count);

    sort_items(items_array, item_count);

    int max_value = pick_items(items_array, item_count, max_weight);

    fprintf(o, "%d", max_value);

    return 0;
}