#include <iostream>
#include <cstring>
#include <fstream>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char c[256];
int words, chars;
int main()
{
    fin.get(c, 256);
    for(int i=0;i<=strlen(c);i++)
        if((c[i]>='a' && c[i]<='z') || (c[i]>='A' && c[i]<='Z'))
        chars++;
    char *p;
    p = strtok (c," ,.-!?");

    while (p != NULL)
    {
        words++;
        p = strtok (NULL, " ,.-!?");
    }
    fout<<chars/words;
    return 0;
}