class Solution {
public int solution(int[] numbers) {
int answer = 0;
boolean visited[] = new boolean[10];
for(int i=0; i<numbers.length; i++){
visited[numbers[i]] = true;
}
for(int i=0; i<visited.length; i++){
if(visited[i] == false){
answer+=i;
}
}
return answer;
}
}