#include<stdio.h>
int main()
{
	char a[102];
	int i,n,sum=0,f=0;
	scanf("%d\n",&n);
	scanf("%s",a);
	for(i=0;i<n-1;i++)
	{
		if(a[i]=='v'&&a[i+1]=='k')
			sum+=1;
		if((a[i]=='v'&&a[i+1]=='v'&&a[i+2]=='v')||(a[i]=='k'&&a[i+1]=='k'&&a[i+2]=='k'))
			f=1;
	}
	printf("%d",sum+f);
	return 0;
}