#include<stdio.h>
#include<math.h>
#define oo 1000000000000000000LL

long long n, m, sol;
FILE *in, *out;

	int main()
	{
		in =  fopen("sek-sek.in", "r");
		fscanf (in, "%lld %lld", &n, &m);
		fclose(in);

		sol = oo;
		long long n1 = n, n2 = 0;
		long long deg = 1LL;
		while (true)
		{
			n2 = n2 + deg * (n1 % 10LL);
			deg = deg * 10LL;
			n1 = n1 / 10LL;
			if (n1 == 0)
				break;

			long long tmp = n1 + n2 - m;
			if (tmp < 0)
				tmp = - tmp;
			if (tmp < sol)
				sol = tmp;
		}

		out = fopen("sek-sek.out", "w");
		fprintf (out, "%lld\n", sol);
		fclose(out);

		return 0;
	}