#include <stdio.h>
#include <string.h>

int main(void){
	int i,j,c,l,m=1000;
	char s[128];
	scanf("%s",s);
	l = strlen(s);
	for(i = 0;i < l;i++){
		if(s[i] != 'c'){continue;}
		c = 0;
		for(j = i+1;j < l;j++){
			if(s[j] == 'w'){c++;}
			if(c == 2){
				if(m > j-i+1){m = j-i+1;}
				break;
			}
		}
	}
	if(m == 1000){printf("-1\n");}else{printf("%d\n",m);}
	return 0;
}