#include <fstream>
#include <cstring> 
#define nm 1200001
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char s[nm],*p;int nr,i,j,lg,n;
int main()
{
    while(fin.getline(s,nm))
    {
    n=strlen(s);
    for(i=0;i<n;i++)
        if((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))
    {
        j=i;
        while((s[j]>='a'&&s[j]<='z')||(s[j]>='A'&&s[j]<='Z'))
            j++,lg++;
        nr++;i=j;
    }
    }
    fout<<lg/nr;
    return 0;
}