#include<fstream>
#include<cstring>
using namespace std;
ifstream in("text.in");
ofstream out("text.out");
int main(){
char s[1000000];
int litere=0,cuvinte=0,i,n;
in.get(s,100000);
in.get();
n=strlen(s);
for(i=0;i<n;i++){
	if((s[i]>='A' && s[i]<='Z') || (s[i]>='a' && s[i]<='z'))
	{
		cuvinte++;
		litere++;
		for(i=i+1;i<n;i++)
			if( (s[i]>='A' && s[i]<='Z') || (s[i]>='a' && s[i]<='z') )
				litere++;
			else break;
	}
}

out<<litere/cuvinte;
}