#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include <string.h>

int main()
{
	int c = -1;
	int w1 = -1;
	int w2 = -1;
	int strNum = 999999999;
	int n = 0;
	char str[100001] = "ccwwcw";

	scanf("%s", str);

	while(true)
	{
		int tmp = 0;

		for (int i = n;str[i] != '\0';i++)
		{
			if (str[i] == 'c' && c == -1)
			{
				c = i;
				break;
			}
		}

		for (int i = c + 1;str[i] != '\0';i++)
		{
			if (str[i] == 'w' && w1 == -1)
			{
				w1 = i;
				break;
			}
		}

		for (int i = w1 + 1;str[i] != '\0';i++)
		{
			if (str[i] == 'w' && w2 == -1)
			{
				w2 = i;
				break;
			}
		}

		if (c == -1 || w1 == -1 || w2 == -1)
		{
			break;
		}

		tmp = w2 - c + 1;

		if (tmp < strNum)
		{
			strNum = tmp;
		}

		c = -1;
		w1 = -1;
		w2 = -1;
		n++;
	}


	if (strNum > 100001)
	{
		printf("-1\n");
		return 0;
	}

	printf("%d\n", strNum );

	return 0;
}