#include <stdio.h>
    int main()
    {

        int i, j, a, n,m;
        scanf("%d",&m);
        scanf("%d", &n);
        int number[n];
        for (i = 0; i < n; i++)
            scanf("%d", &number[i]);

        for (i = 0; i < n; i++)
        {

            for (j = i + 1; j < n; j++)
            {

                if (number[i] > number[j])
                {

                    a =  number[i];
                    number[i] = number[j];
                    number[j] = a;

                }

            }

        }

        for (i = 0; i < n; i++){
 int temp= number[i];
             while(temp)
{
 if(temp%10 == m)
  {printf("%d", number[i]); return 0;}
temp/=10;
}
}


    return 0;
    }