#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int main()
{
    FILE *f=fopen("text.in","r"),*p=fopen("text.out","w");
    char *s,*sep,*a;
    int i,l=0,nr=0;
    sep=" 1234567890~`!@#$%^&*()_{}[]|\'><+=""?:;'-";
    s=malloc(1024*sizeof(char));
    while(fgets(s,1024,f)!=NULL){
    for(i=0;i<strlen(s);i++)
        if((s[i]>='a' && s[i]<='z') || (s[i]>='A' && s[i]<='Z')) {l++;
                                                        //if((s[i+1]==' ') || (s[i+1]=='!') || (s[i+1]=='-') || (s[i+1]==',' ) || (s[i+1]=='?') ||(s[i+1]==';') || (s[i]==':') || (s[i+1]=='(') || (s[i+1]==')') || (s[i+1]=='1') || (s[i+1]=='2') || (s[i]=='3') || (s[i+1]=='4') || (s[i+1]=='5') || (s[i+1]=='6') || (s[i+1]=='7') || (s[i+1]=='8') || (s[i+1]=='9') || (s[i+1]=='0' )) nr++;
                                                        }
    a=strtok(s,sep);
 if (a!=NULL)   nr++;
 while (a!=NULL)
  {nr++;
  a=strtok(NULL,sep);
  }
 nr--;
    }
     if(nr>0) fprintf(p,"%d",l/nr);
        else fprintf(p,"0");
     fclose(f);
     fclose(p);
     return 0;
}