#include <fstream>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
string a;
int i,n,k;
int main()
{
getline(f,a);
for(i=0; i<a.size(); i++)
if(a[i]<'a' and a[i]>'z' or a[i]>'Z' and a[i]<'A' or a[i]!=' ')
    a.erase(i,i+1);
for(i=0; i<a.size(); i++){
    if(a[i]<='z' and a[i]>='a') n++;
    if(a[i]<='Z' and a[i]>='A') n++;
    }

for(i=0; i<a.size(); i++)
    if(a[i]==' ') k++;
k++;
g<<n/k;


    return 0;
}