#include<stdio.h>
int main(){
    int n,i,j,ids[100],found=0;
    scanf("%d",&n);
    if(n<1||n>100)
    printf("Invalid input");
    return 0;
}
for( i=0;i<n;i++){
    scanf("%d",&ids[i]);
}
for(int i=0;i<n;i++){
    for(j=i+1;j<n;j++){
        if(ids[i]==ids[j]){
            printf("%d",ids[i]);
            found=1;
            break;
        }
    }
}
if(!found)
printf("no dupicates found");
return o;
}