/*
 * lab1.c: someone's homework
 *
 * Someone
 * March 21, 2017
 */

#include <stdio.h>
#include <math.h>

/* Defines the valid operations available to the user. */
typedef enum {
    OP_ADD = 'A',
    OP_LOG = 'T',
    OP_TERMINATE = '#'
} Token;

/* Converts a character (either 0 or 1) to an integer value. */
int char_to_bit(char c)
{
    if (c == '0') {
        return 0;
    } else if (c == '1') {
        return 1;
    } else {
        /* FIXME: We receive a newline somewhere in build_number.
         * This code is always executed when accepting a new number.
         * Find a way to get rid of it!
         */
        return 0;
    }
}

/* Appends either a zero or one to a number. */
void append_bit(double *num, char c)
{
    int bit = char_to_bit(c);

    *num *= 2;
    *num += bit;
}

/* Accepts input until OP_TERMINATE is reached and builds an integer
 * from its binary representation.
 */
void build_number(double *num)
{
    char c;

    while ((c = getchar()) != OP_TERMINATE)
    {
        append_bit(num, c);
    }
}

int main(int argc, char *argv[])
{
    double input_1, input_2, result;

    Token tok;
    char c;

    scanf(" %c", &tok);

    switch (tok)
    {
        case OP_ADD:
            build_number(&input_1);
            build_number(&input_2);

            result = input_1 + input_2;

            break;

        case OP_LOG:
            build_number(&input_1);

            result = log10(input_1);

            break;

        default:
            /* TODO: Exit gracefully when no valid operation is given. */
            break;
    }

    printf("%.2f\n", result);

    return 0;
}