#include <iostream>
using namespace std;

int check(string S){
    int clen = 0; int wlen = 0;
    int wcnt = 0; int ccnt = 0;
    for(int i = 0; i < S.size(); ++i){
        if(S[i]=='c'&&ccnt==0){ ccnt+=1; clen = i; }
        if(S[i]=='w'&&ccnt==1){ wcnt+=1; wlen = i+1;}
        if(wcnt == 2){ return wlen - clen; }
    }
    return -1;
}

int main(){
    string S; cin >> S;
    cout << check(S) << endl;
    return 0;
}