#include <stdio.h>
 
int main() {
     
    int b[5] = {5,2,3,1,8};
    int a[11],i;
    int length = sizeof(a) / sizeof (int);
    for(i=0;i<length;i++){
        a[i] = 0;
    }
    a[0] = 0;
     
    for (i=0; i<5; i++) {
        int num = b[i];
        if(a[num] >= 0){
            a[num] ++;
        }else{
            a[num] = 0;
        }
    }
     
    for (i=0; i<11; i++) {
        if(a[i])
            printf("%d\n",i);
    }
     
    return 0;
}