#include<cstdio>
#include<cstring>
int l,i,j,nr,nc;
char s[2000100],*p;
FILE *f,*g;
int main(){
    f=fopen("text.in","r");
    g=fopen("text.out","w");
    fgets(s,3000000,f);
    l=strlen(s);
    p=strtok(s," -,.!?:");
    while(!NULL){
        if(*p=='\n')
            break;
        if((*p>'z'||*p<'a')&&(*p<'A'&&*p>'Z')){
            p=strtok(NULL," -,.!?:");
            continue;
        }
        nr++;
        i=0;
        while((*(p+i)>='a'&&*(p+i)<='z')||(*(p+i)>='A'&&*(p+i)<='Z')){
            nc++;
            i++;
        }
        p=strtok(NULL," -,.!?:");
    }
    fprintf(g,"%d",nc/nr);









    fclose(f);
    fclose(g);
    return 0;
}