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

int main(){
    char cuv[1026], text[1026];
    unsigned long nrCuv=0, litere=0, i, j=0;
    FILE *fin = fopen("text.in", "r");
    FILE *fout = fopen("text.out", "w");
    fgets(text, 1025, fin);
    for(i=0; i<=strlen(text); i++){
	if(!isalpha(text[i])){
	    if(j){
		cuv[j] = 0;
		nrCuv++;
		litere+=strlen(cuv);
		j=0;
	    }
	}else{
	    cuv[j++] = text[i];
	}
    }
    if(j){
	cuv[j] = 0;
	nrCuv++;
	litere+=strlen(cuv);
	j=0;
    }
    if(nrCuv)
	 fprintf(fout, "%lu", litere/nrCuv);
    else
	fprintf(fout, "0");
    fcloseall();
    return 0;
}