#include <iostream>
#include <vector>
#include <cmath>
#include <iomanip>
#include <array>
#include <tuple>
#include <algorithm>
#include <map>
#include <stack>
#include <queue>
#include <set>
#include <list>
#include <cstdio>
#include <limits.h>
#include <string.h>

using namespace std;
using ull = unsigned long long;
using ll = long long;
using ld = long double;
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define GRESORT(v) sort(v.begin(),v.end(),greater<int>())
#define REVERSE(v) reverse(v.begin(),v.end())
#define overlap(v) v.erase(unique(v.begin(),v.end()),v.end())
#define debug(x) cout << #x <<": " << x << endl
#define INF 999999999

int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};

int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);

    string s;
    cin >> s;
    int ans = INT_MAX;
    vector<int> w;
    for(int i = s.size() - 1; i >= 0; i--){
        if(s[i] == 'w') w.push_back(i);
        if(s[i] == 'c' && w.size() > 1){
            ans = min(ans,w[w.size() - 2] - i + 1);
        }
    }
    cout << (ans == INT_MAX ? -1 : ans) << endl;

    return 0;
}