#include <stdio.h>
#include <string.h>

int main()
{
    char bin[40];
    if (scanf("%39s", bin) != 1) return 0;
    
    int len = strlen(bin);
    
    for (int i = 0; i < len; i++)
    {
        if (bin[i] !='0' && bin[i] !='1')
        {
            printf("Invalid Input");
            return 0;
        }
    }
    
    if (bin[0] == '0')
    {
        long long value = 0;
        for (int i = 0; i < len; i++)
        {
            value = value * 2 + (bin[i] - '0');
        }
        printf("%11d", value);
    }
    else
    {
        unsigned long long value = 0ULL;
        for (int i = 0; i < len; i++)
        {
            value = (value << 1) | (unsigned long long)(bin[i] - '0');
        }
        long long signedValue = (long long)(value - (1ULL << len));
        printf("%11d", signedValue);
    }
    return 0;
}