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