#include<stdio.h>
#include<string.h>
int main()
{
	FILE *f,*g;
	f=fopen("text.in", "r");
	g=fopen("text.out", "w");
		char x[1000010];
		int a,c,nr=0,s=0,i=0;
		while(fgets(x,1000000,f));
		i=0;
		c=strlen(x);
		while(i<c)

			{
				while(!((x[i]>='a'&&x[i]<='z')||(x[i]>='A'&&x[i]<='Z')))
					i++;
				a=i;
				while((x[i]>='a'&&x[i]<='z')||(x[i]>='A'&&x[i]<='Z'))
					i++;
				s=s+i-a;
				nr++;
				i++;
			}
    fprintf(g,"%d",s/nr);
	fclose(f);
	fclose(g);
	return 0;
}