#include <iostream>
using namespace std;
int main() {
int n;
cin>>n;
int a[n],b[n];
for(int i=0;i<n;i++)
{
cin>>a[i];
}
int c=0;
for(int i=0;i<n;i++)
{
if(a[i]!=a[i+1])
a[i]=b[i];
cout<<b[i]<<" ";
c++;
}
if(c>0)
cout<<c;
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKaW50IG1haW4oKSB7CgkJaW50IG47CgkJY2luPj5uOwoJCWludCBhW25dLGJbbl07CgkJZm9yKGludCBpPTA7aTxuO2krKykKCQl7CgkJCWNpbj4+YVtpXTsKCQl9CgkJaW50IGM9MDsKCQlmb3IoaW50IGk9MDtpPG47aSsrKQoJCXsKCQlpZihhW2ldIT1hW2krMV0pCgkJYVtpXT1iW2ldOwoJCWNvdXQ8PGJbaV08PCIgIjsKCQljKys7CgkJfQoJCWlmKGM+MCkKCQljb3V0PDxjOwoJCXJldHVybiAwOwp9