#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
using namespace std;

#define ll long long
#define INF (1 << 30)
#define INFLL (1LL << 60)

string str;

int bfs(int now,int how){
	int a,b;
}

int main() {
	cin >> str;
	int ans = INF;
	for(int i = 0;i < str.size();i++){
		if(str[i] == 'c'){
			int how = 0;
			for(int j = i;j < str.size();j++){
				if(str[j] == 'w') how++;
				if(how == 2) {
					ans = min(ans,j-i+1);
					break;
				}
			}
		}
	}
	//cout << INF << endl;
	if(ans == INF) cout << "-1" << endl;
	else cout << ans << endl;
	return 0;
}