#include <fstream>
#include <string.h>
#include <math.h>
using namespace std;

int main()
{
    unsigned int i,j,v,s,l;
    l=0;
    s=0;
    ifstream f("text.in");
    ofstream g("text.out");
    char x[100];
    char m[6]={'.',',',' ','!','?','-'};
    v=0;
    i=0;
    f.getline(x,300);
    if(x[0]=='-')
    v=-1;
    for(i=0;i<strlen(x);i++)
    for(j=0;j<6;j++)
        if((x[i]==m[j])&&(x[i+1]!=' '))
        v++;
    for(i=0;i<strlen(x);i++)
    if(x[i]>='a'&&x[i]<='z'||x[i]>='A'&&x[i]<='Z')
       l++;
g<<l/v;

    return 0;
}