#include<stdio.h>

#define isLetter(a) (((a) >= 'a' && (a) <= 'z') || ((a) >= 'A' && (a) <= 'Z')) ? 1 : 0
inline int len(char *c) { return (*c ? 1 + len(++c) : 0); }

char c[10000];
int total,i,litere;
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    
    while(scanf("%s",c) == 1)
    {
       for(i = 0; i < len(c); i++)
       {
          do
          {    
             while(!isLetter(c[i]) && i < len(c)) i++;
             if(i < len(c))
             {
                total++;
                while(isLetter(c[i]) && i < len(c)) i++,litere++;
             }
          } while(i < len(c));
       }
    }
	
    printf("%d\n",total != 0 ? litere/total : 0);
    
    fclose(stdin); fclose(stdout);
    return 0;
}