{
	ll a[]={0,1,MD};
	unordered_set<ll>z;
	string s;
	rd(s);
	for(int c:s){
		ll b=sum(a(3));
		z.insert(b);
		a[c%3]=b-2a[c%3];
	}
	z.insert(sum(a(3)));
	wt((ll)z.size());
}