#include <cstdio>

using namespace std;
int s, nr, y, w, z;
char x, x1;
int main()
{
    freopen("text.in", "r", stdin);
    freopen("text.out", "w", stdout);
    while(1)
    {
        y=scanf("%c", &x);
        if(y<0) break;
        if(x>='A'&&x<='Z') z++;
        else if(x>='a'&&x<='z') z++;
        else if(x1>='a'&&x1<='z') {s=s+z;z=0;nr++;}
        else if(x1>='A'&&x1<='Z') {s=s+z;z=0;nr++;}
        x1=x;
    }
    w=s/nr;
    printf("%d", w);
    return 0;
}