#include <stdio.h>
#include <string.h>

#define Nmax 8000000

char a[Nmax];
int n,nr,lung;

int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    while(!feof(stdin) )
    {
        gets(a);
        n=strlen(a);
        int i=0;
        while(i<n)
            {
                if((a[i]>='a' && a[i]<='z') || (a[i]>='A' && a[i]<='Z'))
                    {
                        nr++;
                        int tmp=0;
                        while( ( (a[i]>='a' && a[i]<='z') || (a[i]>='A' && a[i]<='Z') ) && i<n )
                            {
                                ++i;
                                ++tmp;    
                            }
                        lung+=tmp;
                    }
			    else
			 	   ++i;
            }
    }
    printf("%d",lung/nr);
    return 0;   
}