// editor2
#include<stdio.h>
int main(){
    int N;
    scanf("%d", &N);
    if(N<1){
        printf("Invalid input");
        return 0;
    }
    if(N>100){
        printf("Invalid input");
        return 0;
    }
    int ids[100];
    for (int i=0;i<N;i++){
        scanf("%d",&ids[i]);
}
int found = 0;
for(int i = 0; i < N;i++){
    for (int j = i + 1; j < N; j++){
        if(ids[i] == ids[j]){
            int alreadyprinted = 0;
            for(int k = 0, k<i ;k++){
                if(ids[k] == ids[i]){
                    alreadyprinted = 1;
                }
            }
            if(!alreadyprinted){
                printf("%d ",ids[i]);
                found = 1;
            }
        }
    }
}
if(!found){
    prinf("No duplicates found");
}
return 0;
}