#include<stdio.h>
 detobi(int a) {
	int stack[10],i=0,r,s;
	do {
		r=a/2;
		s=a%2;
		stack[i]=s;
		if(r!=0) {
			i++;
			a=r;
		}
	}while(r);
	
	for(;i>=0;i--)
		printf("%d",stack[i]);
	printf("\n");

}

int main() {
	int a;
	printf("input a Decimal digit less than 1023\n");
	scanf("%d",&a);
	detobi(a);
	
	return 0;
}