#include <iostream>
#include <cstring>
#include <fstream>

using namespace std;


ifstream f("text.in");
ofstream g("text.out");

int main()
{
    char s[1000001];
    int ctLit=0,ctcuv=1;
    f.get(s,1000001);
    for(int i=0; i<strlen(s); i++)
    {
        if(isalnum(s[i]))
            ctLit++;
        else
        {
            if(isalnum(s[i-1]) and isalnum(s[i+1]))
                ctcuv++;
            if(s[i]==',')
                ctcuv++;
        }

    }
    //cout<<ctLit<<" "<<ctcuv<<endl;
    g<<ctLit/ctcuv;
    return 0;
}