#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
typedef long long ll;

int main()
{
  string s;
  cin >> s;
  int len = 999;
  int slen = s.length();
  FOR(i,0,slen) {
    if(s[i]!='c') continue;
    int w = 0;
    FOR(j,i+1,slen) {
      if(s[j]=='w') w++;
      if(w==2) {
        len = min(len, j - i + 1);
        break;
      }
    }
  }
  cout << (len == 999 ? -1 : len) << endl;
  return 0;
}