#include <fstream>
#include <string.h>
#include <iostream>
using namespace std;

char s[20000001];

int main(){
    ifstream in ("text.in");
    in.getline(s,2000000);
    in.close();
    int i,lung,cuvinte,litere,p;
    cuvinte=0;
    litere=0;
    lung=strlen(s);
    i=0;
    while(i<=lung)
	{
		p=0;
		while(((s[i]>='a')&&(s[i]<='z'))||((s[i]>='A')&&(s[i]<='Z'))){
            p++;
            litere++;
            i++;
        }
		if(p>0)
           cuvinte++;
		i++;
	}
    ofstream out ("text.out");
    out<<litere/cuvinte;
    out.close();
    return 0;
}