POJ1126(AC).cpp

#define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;

int idx;
char s[1000];
int len;
bool suc;

void check(const char s[], int i)
{
	if(!suc){
		return;
	}

	if(i >= len || idx >= len){
		suc = false;
		return;
	}

	switch(s[i]){
	case 'p':
	case 'q':
	case 'r':
	case 's':
	case 't':
	case 'u':
	case 'v':
	case 'w':
	case 'x':
	case 'y':
	case 'z':
		idx = i + 1;
		return;
	case 'C':
	case 'D':
	case 'E':
	case 'I':
		idx = i + 1;
		check(s, idx);
		if(idx >= len){
			suc = false;
			return;
		}else{
			check(s, idx);
			return;
		}
	case 'N':
		idx = i + 1;
		check(s, idx);
		return;
	default:
		suc = false;
		return;
	}
}


int main()
{
	while(scanf("%s", s) == 1){
		len = strlen(s);
		idx = 0;
		suc = true;
		check(s, 0);

		if(idx != len){
			suc = false;
		}

		if(suc){
			printf("YES\n");
		}else{
			printf("NO\n");
		}
	}

	return 0;
}