#include <stdio.h>

enum
{
    BUF_SIZE = 1024,
    TABLE_OFFSET = 22,
    TABLES_COUNT = 1024,
    TABLE_SIZE = 4096
};

int
main(void)
{
    char buf[BUF_SIZE];
    int tables[TABLES_COUNT] = {0};
    int i;
    long long int sum = 0;
    unsigned int from, to;
    while (fgets(buf, BUF_SIZE, stdin) > 0) {
        sscanf(buf, "%x-%x", &from, &to);
        from >>= TABLE_OFFSET;
        to--;
        to >>= TABLE_OFFSET;
        for (i = from; i <= to; i++) {
            tables[i] = 1;
        }
    }
    for (i = 0; i < TABLES_COUNT; i++) {
        if (tables[i]) {
            sum += TABLE_SIZE;
        }
    }
    if (sum > 0) {
        sum += TABLE_SIZE;
    }
    printf("%lld\n", sum);
    return 0;
}