#include <bits/stdc++.h>
using longlong=long long;

[[maybe_unused]]auto cmn=[](auto&& a,auto b){if(a>b){a=b;return true;}return false;};
[[maybe_unused]]auto cmx=[](auto&& a,auto b){if(a<b){a=b;return true;}return false;};

int main(){
    std::cin.tie(nullptr);std::cin.sync_with_stdio(false);
    std::string s;std::cin>>s;
    int n=s.length();
    int ans=n+1;
    for(int i=0;i<n;i++){
        if(s.at(i)!='c')continue;
        int j=i+1;
        while(j<n&&s.at(j)!='w')j++;
        j++;
        while(j<n&&s.at(j)!='w')j++;
        if(j==n)continue;
        cmn(ans,j-i+1);
    }
    if(ans==n+1)ans=-1;
    std::cout<<ans<<std::endl;
}