import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        long s = sc.nextInt();
        long n = str.length();
        int tot = 0;
        long[] a = new long[100031];
        long[][] num = new long[55][55], dp = new long[55][100031];

        for (int i = 0; i < str.length(); i++) {
            if (str.charAt(i) != '0') {
                a[++tot] = str.charAt(i) - '0';
            }
        }

        for (int i = 1; i <= tot; i++) {
            num[i][i] = a[i];
            for (int j = i; j - i <= 11 && j <= tot; j++) {
                num[i][j] = num[i][j - 1] * 10 + a[j];
            }
        }

        for (int i = 0; i <= tot + 1; i++) {
            for (int j = 0; j <= s + 1; j++) {
                dp[i][j] = Integer.MAX_VALUE;
            }
        }

        dp[0][0] = 0;

        for (int i = 1; i <= tot; i++) {
            for (int k = 1; k <= 11; k++) {
                if (i >= k) {
                    for (int j = (int) num[i - k + 1][i]; j <= s; j++) {
                        dp[i][j] = Math.min(dp[i][j], dp[i - k][j - (int) num[i - k + 1][i]] + 1);
                    }
                }
            }
        }

        if (dp[tot][(int) s] > tot) System.out.println(-1);
        else System.out.println(dp[tot][(int) s] - 1);

        sc.close();
    }
}