#include <stdio.h>

int i, j, count, min = 101;
char s[101];

int main(void) {
	scanf("%s", s);
	
	while(s[i] != '\0') {
		if(s[i] == 'c') {
			count = 0;
			j = i;
			while(s[j] != '\0') {
				if(s[j] == 'w') { count++; }
				if(count == 2) {
					min = ( (j - i + 1) < min ? (j - i + 1) : min );
					break;
				}
				j++;
			}
		}
		i++;
	}
	
	printf("%d\n", (min == 101 ? -1 : min));
	
	return 0;
}