#include <stdio.h>

int main() {
    unsigned int n;
    printf("Zahl zur Umrechnung ins Binärsystem: "); 
    if (scanf("%u", &n) != 1) return 255;
    if (n > 0) {
        unsigned int reverse = 0; // n with all bits reverted
        unsigned int len = 0;  // length of binary number without leading zeros of n
        unsigned int h = n;
        while (h > 0) {
            reverse = (reverse << 1) | (h & 1);
            h >>= 1;
            ++len;
        }
        for (int i = 0; i < len; ++i, reverse >>= 1) {
            if (reverse & 1) {
                putchar('1');
            } else {
                putchar('0');
            }
        }
   } 
   else {
      printf("0");
   }
   putchar('\n');
}