#include <stdio.h>
extern char getchar_unlocked(void);
#define gc(c)	do{c=getchar_unlocked();}while(0)
int main( void ) {
int	cnt=0;
char c;
gc(c);while(c!=EOF){if(c=='\n')break;if(c=='n')cnt++;gc(c);}
printf("%d\n", cnt );
}