#include <stdio.h> int main() { int x; scanf("%d",&x); int a[10005]; int b[10005]; for ( int i=0;i<x;i++) { scanf("%d",&a[i]); } for ( int i=0;i<x-1;i++) { for ( int j=0;j<x-1-i;j++) { if ( a[j]>a[j+1]) { int temp = a[j]; a[j]=a[j+1]; a[j+1]=temp; } } } int count = 0; for ( int i = 0; i < x; i++) { if (i == 0 || a[i] != a[i - 1]) { b[count++] = a[i]; } } printf("%d\n",count); for ( int i=0;i<count;i++) { printf("%d ",b[i]); } return 0; }