#include <stdio.h>

int main()
{
	char S[101];
	int len, mincwwlen = 0;

	scanf("%s%n", &S, &len);

	mincwwlen = len + 1;

	for (int i = 0; i < len; i++)
	{
		if (S[i] == 'c')
		{
			int cwwlen = 0, cww = 0;
			for (int j = i; j < len; j++)
			{
				cwwlen++;
				if (S[j] == 'w')
				{
					cww++;
				}

				if (cww == 2)
				{
					if (cwwlen < mincwwlen)
					{
						mincwwlen = cwwlen;
					}
					break;
				}
			}
		}
	}

	if (mincwwlen == len + 1)
	{
		mincwwlen = -1;
	}

	printf("%d", mincwwlen);

	return 0;
}