#include <stdio.h>
#include <string>
int main(){
    //input
    char S[101];
    scanf("%s",S);
    std::string str(S);

    //search
    int mLength = 101;
    for (int i = 0;i < str.length();i++){
        if (str[i] == 'c'){
            int count_w = 0;
            for (int j = i+1;j < str.length();j++){
                if (str[j] == 'w'){
                    count_w++;
                }
                if (count_w == 2){
                    int cLength = j-i+1;
                    if (cLength < mLength){
                        mLength = cLength;
                    }
                }
            }
        }
    }

    //output
    if (mLength != 101){
        printf("%d\n",mLength);
    }else{
        printf("%d\n",-1);
    }
    return 0;
}