#include<bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
int main(){
	string S;
	cin>>S;
	int c=0;
	REP(i,S.size()){
	    if(S[i]=='w')break;
	    c++;
	}
	int w=S.size()-c;
        cout<<min(c-1,w)<<endl;
	return(0);
}