#define _USE_MATH_DEFINES
 
#include <iostream>
#include <iomanip>
#include <sstream>
 
#include <algorithm>
#include <cmath>
 
#include <string>
#include <queue>
#include <vector>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <valarray>

#include<cassert>//assert();
//#include <random>//xAOJ
/////////
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define P(p) cout<<(p)<<endl;
 
#define PII pair<int,int>
/////////
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
/////////
using namespace::std;
/////////
/////////

void solve(){
	string str;
	cin >> str;
	string cww = "cww";
	int len = str.length();
	int w1,w2;
	int ans = 200;
	for(int i=0;i<len;++i){
		if( str[i] == cww[0]){
			w1 = -1;
			w2 = -1;
			for(int j=i+1;j<len;++j){
				if( str[j] == cww[1] ){
					w1 = j;
					break;
				}
			}
			
			if( w1 != -1 ){
				for(int k=w1+1;k<len;++k){
					if( str[k] == cww[2] ){
						w2 = k;
						break;
					}
				}
			}
			if( w2 != -1){
				ans = min(ans,w2-i+1);
			}
		}
	}
	if( ans == 200 ){
		cout << -1 << endl;
	}else{
		cout << ans << endl;
	}
}

int main(void){
    std::cin.tie(0); 
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed;//
    //cout << setprecision(16);//
	
	solve();
	
	return 0;
}