#include <iostream>
using namespace std;
int min(int n[]){
    int i,m=1000;
    for(i=0;n[i];i++) if(n[i]<m)m=n[i];
    return (m==1000?-1:m);
}
int main(){
    int i=0,a=0,n=0,che=1,cnt[1000]={},result;
    char c[1000];
    bool cw=false,w=false,cheSrt=false,mybusiness=true;
    cin>>c;
    for(i=0;i<1000;i++){
        if(c[i]<97||122<c[i]) break;
        if(cw){
            if(c[i]=='w'){
                if(w){
                    cnt[a]=che;
                    if(cnt[a]==3)break;
                    che=1;
                    a++;
                    w=false;
                    if(n){i=n;n=0;mybusiness=true;}else{cw=false;cheSrt=false;}
                }else{
                    w=true;
                }
            }else if(c[i]=='c'&&mybusiness){
                if(w){
                    n=i;
                    mybusiness=false;
                }else{
                    che=1;
                }
            }
        }else if(c[i]=='c'){
            cw=true;
            cheSrt=true;
        }
        if(cheSrt)che++;
    }
    result=min(cnt);
    cout<<result<<"\n";
    return 0;
}