#include <stdio.h>
#include <ctype.h>

using namespace std;

int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
   // char x;
    char y;
    //scanf("%d",&x);
    int s=0;
    int nr=0;
    while(!feof(stdin))
    {
        scanf("%c",&y);
        if(isalpha(y))
        {
            nr++;
            while(!feof(stdin) && isalpha(y))
            {
                s++;
                scanf("%c",&y);
            }
        }
    }
    printf("%d",s/nr);

    return 0;
}