#include<iostream>
#include<vector>
#include<string>
#include<cstdio>
#include<algorithm>
using namespace std;
int main(){
    string str;
    int ans=100000,count;
    cin >> str;
    for(int i=0;str[i]!='\0';i++){
        if(str[i]=='c'){
            count =0;
            for(int j=i;str[j]!='\0';j++){
                if(str[j]=='w'){
                    count++;
                }
                if(count==2)    ans = min(ans,j-i+1);
            }
        }
    }
    if(ans==100000)   cout << "-1";
    else cout << ans;
    return 0;
}