//No.345 最小チワワ問題
#pragma GCC optimize("O3")
#pragma GCC target("avx")
#include <bits/stdc++.h>
#define rep(i ,n) for(int i=0;i<(int)(n);++i)

using namespace std;

signed main(){
    string s; cin >> s;
    int ans = (int)10e8;
    rep( i , s.size()-2){
        if(s[i] == 'c'){
            for( int j = i + 1 ; j < s.size() - 1 ; ++j){
                if( s[j] == 'w'){
                    for( int k = j + 1 ; k < s.size() ; ++k){
                        if( s[k] == 'w') {
                            int diff = k - i + 1;
                            ans = min( ans , diff);
                        }
                    }
                }
            }
        }
    }
    if( ans == (int)10e8 ) cout << -1 << endl;
    else cout << ans << endl;
}