#include<stdio.h>
#include<string.h>
int main()
{
	char s[102];
	scanf("%s", s);
	int i, j, k, n = strlen(s);
	int ans = 4649;
	for (i = 0; i < n - 2; i++)
		for (j = i + 1; j < n - 1; j++)
			for (k = j + 1; k < n; k++)
				if (s[i] == 'c' && s[j] == 'w' && s[k] == 'w')
					if (ans > k - i + 1)
						ans = k - i + 1;
	if (ans > 100)
		ans = -1;
	printf("%d\n", ans);
	return 0;
}