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

int main()
{
	char N[11];
	scanf("%s", N);

	int l = strlen(N);
	int n = l % 3;
	if (n > 0)
		fwrite(N, 1, n, stdout);
	for ( ; n < l; n += 3) {
		if (n > 0)
			fwrite(",", 1, 1, stdout);
		fwrite(N+n, 1, 3, stdout);
	}
	fwrite("\n", 1, 1, stdout);
	return 0;
}