#include <iostream>
#include <fstream>
#include <string.h>

using namespace std;

int main()
{char s[100];
int i=0;
    ifstream f2("text.in");
    ofstream g("text.out");
    f2.get(s,100);
int nr=0,sum=0;
for(i=0;i<strlen(s);i++)
if(s[i]>='a'&&s[i]<='z'||s[i]>='A'&&s[i]<='Z')sum++;
 else
if(s[i-1]>='a'&&s[i-1]<='z'||s[i-1]>='A'&&s[i-1]<='Z')nr++;
    g<<sum/nr;
    return 0;

}