#include <stdio.h>
int main()
{
    int x, n,r,d,mile;
    scanf("%d %d", &x, &n);
    if (n == 0)
    {
        printf("0");
    }
    r = n / 7;
    d = n % 7;
    switch (x)
    {
    case 1:
        if (d <= 5)
        {
            mile = d * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d >= 5 && d <= 7)
        {
            mile = (r + 1) * 5 * 250;
            printf("%lld", mile);
        }
        break;
    case 2:
        if (d <= 4)
        {
            mile = d * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d > 4 && d <= 6)
        {
            mile = 4 * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d == 7)
        {
            mile = (r + 1) * 5 * 250;
            printf("%lld", mile);
        }
        break;
    case 3:
        if (d <= 3)
        {
            mile = d * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d > 3 && d <= 5)
        {
            mile = 3 * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d > 5&&d <= 7)
        {
            mile = 3 * 250 + r * 5 * 250 + (d - 5) * 250;
            printf("%lld", mile);
        }
        break;
    case 4:
        if (d <= 2)
        {
            mile = d * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d > 2 && d <= 4)
        {
            mile = 500 + r * 5 * 250;
            printf("%lld", mile);
        }
        else if (d > 4 && d <= 7)
        {
            mile = 500 + r * 5 * 250 + (d - 4) * 250;
            printf("%lld", mile);
        }
        break;
    case 5:
        if (d == 1)
        {
            mile = 250 + r * 250 * 5;
            printf("%lld", mile);
        }
        else if (d > 1 && d <= 3)
        {
            mile = 250 + r * 250 * 5;
            printf("%lld", mile);
        }
        else if (d > 3 && d<= 7)
        {
            mile = 250 + r * 5 * 250 + (d - 3) * 250;
            printf("%lld", mile);
        }
        break;
    case 6:
        if (d <= 2)
        {
            printf("%lld", r * 5 * 250);
        }
        else if (d > 2)
        {
            mile = (d - 2) * 250 + r * 5 * 250;
            printf("%lld", mile);
        }
        break;
    case 7:
        if (d == 1)
        {
            printf("%lld", r * 5 * 250);
        }
        else if (d >= 2 && d <= 6)
        {
            mile = (d - 1) * 250 + r * 250 * 5;
            printf("%lld", mile);
        }
        else if (d == 7)
        {
            mile = (r + 1) * 5 * 250;
            printf("%lld", mile);
        }
        break;
    }
    return 0;

}