#include <stdio.h>
#include <stdlib.h>
int main()
{
    int a,k=0,t=1,s;
    FILE *fin,*fout;
    fin=fopen("text.in", "r");
    fout=fopen("text.out", "w");
    while((a=fgetc(fin))!=EOF)
    {
        if(((a>47)&&(a<58))||((a>64)&&(a<90))||((a>96)&&(a<123)))
            {k++;
            s=1;
            }
        if(((a==32)||(a==45))&&(s==1))
        t++;
    }
    fprintf(fout,"%d",k/t);
    return 0;
}