tong:array[-1000..1000]of longint;
begin
readln(n);
for i:=1 to n do
begin
read(x);
tong[x]:=1;
end;
for i:=-1000 to 1000 do
if tong[i]=1 then
begin
k1:=k1+1;
end;
writeln(k1);
for i:=-1000 to 1000 do
if tong[i]<>0 then
begin
inc(k2);
if k2=1 then write(i) else write(' ',i);
end;
end.
using namespace std;
int a[101],x,y,z,i,j,k,n,m,b[101],tot;
int paixu(int *a,int n)
{
int zhi,bao;
for(int i=1;i<=n;i++)
{
bao=a[i];
zhi=i-1;
while((zhi>=0)&&(bao<a[zhi]))
{
a[zhi+1]=a[zhi];
zhi--;
}
a[zhi+1]=bao;
}
}
int shanchu(int *a,int n)
{
int zhi;
for(int i=1;i<=n;i++)
{
if(a[i]!=a[i-1])
tot++;
}
}
int main()
{
cin>>n;
for(i=1;i<=n;i++)
cin>>a[i];
paixu(a,n);
shanchu(a,n);
cout<<tot<<endl;
cout<<a[1];
for(i=2;i<=n;i++)
{
if(a[i]!=a[i-1]) cout<<" "<<a[i];
}
}
#include<iostream>
using namespace std;
int a[101],x,y,z,i,j,k,n,m,b[101],tot;
int paixu(int *a,int n)
{
int zhi,bao;
for(int i=1;i<=n;i++)
{
bao=a[i];
zhi=i-1;
while((zhi>=0)&&(bao<a[zhi]))
{
a[zhi+1]=a[zhi];
zhi--;
}
a[zhi+1]=bao;
}
}
int shanchu(int *a,int n)
{
int zhi;
for(int i=1;i<=n;i++)
{
if(a[i]!=a[i-1])
tot++;
}
}
int main()
{
cin>>n;
for(i=1;i<=n;i++)
cin>>a[i];
paixu(a,n);
shanchu(a,n);
cout<<tot<<endl;
cout<<a[1];
for(i=2;i<=n;i++)
{
if(a[i]!=a[i-1]) cout<<" "<<a[i];
}
}//很慢的啦