#include<stdio.h>
main(){
    char S[101];
    scanf("%s",S);
    int min = 101;
    for(int i = 0;S[i] != '\0';i++){
        if(S[i] != 'c'){
            continue;
        }
        int cnt = 0;
        for(int j = i+1;S[j] != '\0';j++){
            if(S[j] == 'w'){cnt++;}
            if(cnt==2){
                if(j-i+1<min){min = j-i+1;}
                break;
            }
        }
    }
    printf("%d\n",min==101?-1:min);
}