#include <bits/stdc++.h>

using namespace std;

ifstream fin("text.in");
ofstream fout("text.out");

char c[1050000];

int main()
{
    fin.get(c,1050000);
    int l=strlen(c),i=0;
    int lc=0,nr=0;
    while(i<l){
        while(((c[i]>'Z' && c[i]<'a') || (c[i]<'A' || c[i]>'z')) && i<l) ++i;
        while(((c[i]>='A' && c[i]<='Z') || (c[i]>='a' && c[i]<='z')) && i<l) {
            if((c[i]<='z' && c[i]>='a') || (c[i]>='A' && c[i]<='Z')) ++lc;
            ++i;
        }
        ++nr;
    }
    fout<<lc/nr;
    return 0;
}