#include <stdio.h>
#include <stdlib.h>

int main(void){

    char buf[100] = {};
    char str[] = "cww";
    int i = 0, j = 0;

    fgets(buf, sizeof(buf), stdin);
    while(buf[i] != '\0'){
        if(buf[i] == str[j]){
            j++;
            if(j == (sizeof(str)) - 1){
                printf("%d\n", i+1);
                exit(0);
            }
        }
        i++;
    }
    printf("-1\n");    
    return 0;
}