#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char c[1500000001];
int n, i, l, cuv;
int main()
{
    f.getline(c, 1000000);
    n=strlen(c);
    for(i=0; i<n; i++)
        {
            if((c[i]>='A'&&c[i]<='Z')||(c[i]>='a'&&c[i]<='z')||(c[i]>='0'&&c[i]<='9')) l++;
                else if((c[i]=='-'||c[i]==' '||c[i]=='.'||c[i]==','||c[i]==';'||c[i]=='!'||c[i]=='?')&&((c[i-1]>='A'&&c[i-1]<='Z')||(c[i-1]>='a'&&c[i-1]<='z')||(c[i-1]>='0'&&c[i-1]<='9')))
                    cuv++;
        }
    if(cuv==0) g<<0;
        else g<<l/cuv;
    return 0;
}