#include<stdio.h>
int main() {
    int N;
    scanf("%d", &N);
    if(N<1) {
        printf("Invalid input");
        return 0; 
        
    }
    int ids[N];
    for(int i=0; i<N; i++) {
        scanf("%d", &ids[i]);
        }
        int duplicatesFound==0;
        for(int i=0; i<N; i++) {
            int count=0;
             for(int j=0; j<N; j++) {
                 if (ids[i] == ids[j]){
                   count++;  
                 }
        }
        if(count>0) {
            int alreadyPrinted = 0;
            for(int k=0; k<i; k++) {
                if(ids[k]==ids[i]) {
                    alreadyPrinted=1;
                    break;
                }
            }
            if(!alreadyPrinted) {
                printf("%d", ids[i]);
                duplicatesFounds=1;
            }
        }
}
        if(!duplicatesFound) {
            printf("No Duplicates Found");
            return 0;
        }
}