include<stdio.h>

include<cs50.h>

int main(void)
{
int i, j, sum1, sum2, sum, card;
i = 0;
j = 0;
sum1 = 0;
sum2 = 0;
sum = 0;
long n, temp;
n = get_long("Number: ");
temp = n;
while (n > 0)
{
i = n%10;
n = n/100;
/ if (n/100 == 0)
{
card = n;
} /
sum1= sum1 + i;
}

i = 0;
n = temp/10;

while (n > 0)
{
    i = n%10;
    n = n/100;
    i = i * 2;
    if (i/10 > 0)
    {
        j = i%10;
        i = i/10;
        i = i + j;
    }
    sum2 = sum2 + i;
}

sum = sum1 + sum2;

if (sum%10 == 0 && n > (10^13))
{
    /* if (card == 34 || card == 37)
    {
        printf("AMEX\n");
    }
    else if (card == 51 || card == 52 || card == 53 || card == 54 || card == 55)
    {
        printf("MASTERCARD\n");
    }
    else
    {
        printf("VISA\n");
    }
    */

    n = temp;
    if (n % (10^13) == 34 || n % (10^13) == 37)
    {
        printf("AMEX\n");
    }
    else if (n % (10^14) <= 55 && n % (10^14) >=51)
    {
        printf("MASTERCARD\n");
    }
    else if (n % (10^12) == 4 || n % (10^15) == 4)
    {
        printf("VISA\n");
    }
    else 
    {
        printf("INVALID\n");
    }
}
else
{
    printf("INVALID\n");
}

}