import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
boolean[] fs = new boolean[10001];
for(int i = 0; i < 9997; i++) {
fs[sc.nextInt()] = true;
}
String ans = "";
for(int i = 1; i < 10001; i++) {
if(!fs[i]) {
ans += i;
}
}
System.out.println(Long.parseLong(ans) % 7);
}
}