#include <iostream>
#include <fstream>

using namespace std;
ifstream fin("date.in");
ofstream fout("text.out");

int main()
{
    char c1,c2;
    int nrlit=0,n=0;
    fin.get(c2);
    if(((int)c2>=65 && (int)c2<=90) || ((int)c2>=97 && (int)c2<=122)) nrlit++, n++;
    fin.get(c1);
    while(!fin.eof())
    {
        if(((int)c1>=65 && (int)c1<=90) || ((int)c1>=97 && (int)c1<=122))
        {
            nrlit++;
            if(!(((int)c2>+65 && (int)c2<=90) || ((int)c2>=97 && (int)c2<=122))) n++;
        }
        c2=c1;
        fin.get(c1);
    }
    cout<<nrlit/n;
    return 0;
}