#include <bits/stdc++.h>
using namespace std;

int main(){
    string s;
    cin >> s;

    //一番右のcを探す
    int last_c = s.size();
    int loop = 0;
    int size = s.size();
    int res[100] = {0};

    while(1){
        int count_w = 0;
        for(int i = 0; i < size; i++){
             if(s[i] == 'c'){
                last_c = i;
            }
        }

        size = last_c;
        //一番右のcからwが二つ目まで探す
        for(int i = last_c; i < s.size(); i++){
            if(s[i] == 'w'){
                count_w++;
            }
            if(count_w == 2){
                res[i] = i-last_c+1;
                // cout << res[i] << endl;
            }
        }

        loop++;
        if(loop > 100) break;
    }
    bool out_res = false;
   sort(res, res + 100);
   for(int i = 0; i < 100; i++){
       if(res[i] != 0){
           cout << res[i] << endl;
           out_res = true;
           break;
       }
   }
   if(out_res == false) cout << -1 << endl;
}