#include<iostream>
#include<algorithm>
#include<cstdio>
#include <vector>
using namespace std;
int main( )
{
	string s;
	cin >> s;
	int len = s.length( );
	int ans = 0;
	ans += 1;
	for( int i = 1; i < len; ++ i )
	{
		ans ++;
		if( s[i] == s[i - 1] )
		{
			i ++;
		}
	}
	cout << ans << endl;
}