#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>
using namespace std;
#define lint long long int
/*
vector<char>al(26);
al = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
vector<char>AL(26);
AL = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
*/

int main() {
	string S;
	cin >> S;
	int Z = S.size();
	int cnta = 0;
	for (int i = 0; i < Z; i++) {
		if (S.at(i) == 'c' || S.at(i) == 'w') {
			cnta++;
		}
	}
	vector<char>vecc(cnta);
	vector<int>veci(cnta);
	int cntb = 0;
	int cntc = 0;
	for (int i = 0; i < Z; i++) {
		if (S.at(i) == 'c' || S.at(i) == 'w') {
			vecc.at(cntb) = S.at(i);
			veci.at(cntb) = cntc;
			cntb++;
			cntc++;
		}
		else {
			cntc++;
		}

	}
	/*for (int i = 0; i < cnta; i++) {
		cout << vecc.at(i) << ' ' << veci.at(i) << endl;
	}*/
	vector<int>vec(1000);
	int cntd = 0;
	for (int i = 0; i < cnta-2; i++) {
		if (vecc.at(i) == 'c' && vecc.at(i + 1) == 'w' && vecc.at(i + 2) == 'w') {
			vec.at(cntd) = veci.at(i + 2) - veci.at(i);
			cntd++;
		}
	}
	/*for (int i = 0; i < 100; i++) {
		cout << vec.at(i) << ' ';
	}*/
	sort(vec.rbegin(), vec.rend());
	if (vec.at(0) == 0) {
		cout << -1 << endl;
	}
	else {
		cout << vec.at(0) + 1 << endl;
	}
}