#include<fstream>
#include<string>
#define isA(a) (a>='a'&&a<='z' || a>='A'&&a<='Z' || a>='0'&&a<='9')
using namespace std;
char c[10000];
long nrcuv, nr,i;
int main()
{
	ifstream f("text.in");
	ofstream g("text.out");
	f.getline(c,10000);
	for(i=0;i<strlen(c);i++)
	{
		if(isA(c[i]))
			nr++;
		if(isA(c[i]) && !isA(c[i-1]))
			nrcuv++;
	}
	g<<nr/nrcuv;
}