#include<stdio.h>

int main(int argc, char const *argv[]) {
    /* code */
    char str[256];
    int wp = 0, wp_c = 0, i = 0, j = 0;
    int flag = 0, cnt = 256;
    int start[256] = {0};

    while(fscanf(stdin, "%c", &str[wp]) != EOF){
        wp++;
    }
    //printf("wp = %d\n", wp);
    for(i = 0; i < wp; i++){
        if(str[i] == 'c'){
            start[wp_c++] = i;
            //printf("start[%d] = %d\n", wp_c - 1, i);
        }
    }

    for(i = 0; i < wp_c; i++){
        j = 0;
        while(start[i] + j++ < wp){
            if(str[start[i] + j] == 'w'){
                while(start[i] + j++ < wp){
                    if(str[start[i] + j] == 'w'){
                        if(cnt > j){
                            cnt = j + 1;;
                            flag = 1;
                        }
                        break;
                    }
                }
                break;
            }
        }
    }

    if(flag == 1){
        fprintf(stdout, "%d\n", cnt);
    }else{
        fprintf(stdout, "-1\n");
    }

    return 0;
}