#include<iostream>
#include<string>

int find(std::string s,int pos) {
    int count=0, i=pos;
    for(;i<s.size() && count!=2;++i) {
        if(s[i]=='w') ++count;
    }
    if(count==2)
        return i-pos;
    else
        return -1;
}

int main() {
    const char ptn[] = "cww";
    std::string s;std::cin>>s;
    int minimum=200;
    for(int i=0;i<s.size();++i) {
        if(s[i]=='c') {
            int length = find(s,i);
            if(length>0)
                minimum = std::min(length, minimum);
        }
    }
    int ans= (minimum==200) ? -1 : minimum ;
    std::cout << ans << std::endl;
}