#include<fstream.h>
#include<string.h>

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

int main()
{char a[100000];
long s=0,nr=0;
int i=0;
fin.get(a,100000);
while(i<strlen(a))
 if((a[i]>='a' && a[i]<='z' )||(a[i]>='A' &&a[i]<='Z'))
     {nr++;
     while((a[i]>='a' && a[i]<='z' )||(a[i]>='A' &&a[i]<='Z'))
        {i++;
        s++;
        }
     }
    else i++;
fout<<s/nr;
fin.close();
fout.close();
return 0;
}