strlen666!

#include<cstdio>
#include<cstring>
int main(){
    char s[1000001];int noon=0;
    scanf("%s",s);
    for(int i;i<strlen(s)-3;i++){
        if(s[i]=='N'&&s[i+1]=='O'&&s[i+2]=='O'&&s[i+3]=='N'){
            noon++;
        }
    }
    printf("%d",noon);
}