#include <stdio.h>

int main(void)
{
	int i, j, m = 100, c;
	char s[101] = {};
	scanf("%s", &s);

	for( i = 0; s[i] != NULL; i++) {
		if(s[i] == 'c') {
			c = 0;
			for( j = i+1; s[j] != NULL && c != 2; j++) {
				if( s[j] == 'w' ) c++;
				if( c == 2 && j-i+1 < m) m = j-i+1;
			}
		}
	}
	if( m == 100 ) {
		printf("-1\n");
		return 0;
	}
	printf("%d\n", m);
	return 0;
}