#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>

int is_letter(unsigned char A)
{
	if ((A >= 'a' && A <= 'z') || (A >= 'A' && A <= 'Z'))
		return 1;
	return 0;
}



int main()
{
	FILE* f = fopen("text.in", "rt");
	unsigned char text[1000000];
	unsigned long count = 0, len=0, sum=0;

	fgets(text, 1000000, f);

	//printf("%s \n", text);


	for (int i = 0; text[i]!='\0'; i++)
	{
		
		if (is_letter(text[i]))
			len++;
		else
			if (len != 0)
				if (len == 1)
					len = 0;
				else
				{
					sum = sum + len;
					len = 0;
					count++;
				}
		//printf("Letter: %c Count: %u Lenght: %u Total: %u \n", text[i], count, len, sum);
	}

	sum = sum / count;
	
	f = fopen("text.out", "wt");
	fprintf(f, "%lu \n", sum);
	fflush(stdout);
	fclose(f);
	return 0;
}