#include <iostream>
using namespace std;
int main() {
    string s;
    cin >> s;
    int cnt=0;
    int begin=-1, end=0, w_cnt=0;
    for(int i=0;i<s.size();i++) {
        if(s[i]=='c') begin=i;
        if(begin!=-1 && s[i]=='w' && w_cnt==1) end=i;
        if(begin!=-1 && s[i]=='w') w_cnt++;
    }
    if(end==0)
        cout << -1 << endl;
    else
        cout << end-begin+1<<endl;
}