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

void solve();
int main() {
	solve();
#ifdef DBG
	while (true);
#endif
}

//336
void solve() {
	char s[100001];
	scanf("%s", s);
	int c, cc = 0;
	for (c = 0; s[c]; c++);
	for (cc = 0; s[cc] != 'w'; cc++);
	printf("%d\n", min(cc - 1, c - cc));
}