#include <stdio.h>
#include <algorithm>
#include <deque>
using namespace std;
using ll = long long;

int main() {
	char s[101] = { 0 };
	scanf("%s", s);
	int mins = 1000;
	deque<int> c, w;
	for (int i = 0; s[i] != 0; i++) {
		if (s[i] == 'c')
			c.emplace_back(i);
		if (s[i] == 'w') {
			if (2 <= w.size())
				w.pop_front();
			w.emplace_back(i);

			while (2 <= c.size() && c[1] < w[0])
				c.pop_front();
			if (1 <= c.size() && 2 <= w.size() && c[0] < w[0])
				mins = min(mins, w[1] - c[0] + 1);
		}
	}
	printf("%d\n", mins != 1000 ? mins : -1);
}