import java.util.Scanner; 
import java.lang.String; 
import java.util.regex.*;
class A{ 
public static void main(String args[])
{ 
int count=0; 
Scanner sc = new Scanner(System.in); 
String s=sc.next(); 
boolean a=true; 
while(a){ 
Pattern p = Pattern.compile("min-*n"); 
Matcher m = p.matcher(s); 
a = m.find(); 
count++;  
} 
System.out.print(count); 
} 
}