#include <cstring>
#include <fstream>
using namespace std;
ifstream cin("text.in");
ofstream cout("text.out");
int i,n,v[100002],j,sum,nr;
char s[100000001],*p;
int main()
{
  cin.getline(s,100000001);
  p=strtok(s," -1234567890  *()&^%$#@!.?,/<>'';:][}\{|}]~`-_=+");
while(p)
{
  n=strlen(p);
  sum+=n;
  nr++;
  p=strtok(NULL," -1234567890  *()&^%$#@!.?,/<>'';:][}\{|}]~`-_=+");
}
cout<<sum/nr;
}