#include <iostream>

#include <cmath>

using namespace std;

bool broken[10];

int check(int n)

{

int res = 0;

if (n == 0 && broken[0])

return 0;

else if (n == 0)

return 1;

while (n > 0)

{

if (broken[n % 10])

return 0;

n = n / 10;

res++;

}

return res;

}

int main()

{

int i, N, M, x;

cin >> N >> M;

for (i = 0; i < M; i++)

{

cin >> x;

broken[x] = true;

}

int ans = abs(N - 100);

for (i = 0; i <= 1000000; i++)

{

x = check(i);

if (x > 0)

{

ans = min(ans, x + abs(N - i));

}

}

cout << ans << "\n";

return 0;

}