#include<fstream>
#include<cstring>
#include<cctype>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char s[300];
int i,nrc,nrl;
int main()
{
    f.get(s,300);
    for(i=0;i<=strlen(s)-1;i++){
        if(isalpha(s[i]))
           nrl++;
        if(!isalpha(s[i]) and s[i]!=',' and s[i]!='?' and s[i]!='!' and s[i]!='.' and i)
            nrc++;
    }
    g<<nrl/nrc;
    return 0;
}