Problem:
Score : 200 points

Problem Statement

Snuke lives on an infinite two-dimensional plane. He is going on an N-day trip.
At the beginning of Day 1, he is at home. His plan is described in a string S of length N.
On Day i(1 ≦ i ≦ N), he will travel a positive distance in the following direction:

North if the i-th letter of S is N

West if the i-th letter of S is W

South if the i-th letter of S is S

East if the i-th letter of S is E

He has not decided each day's travel distance. Determine whether it is possible to set each day's travel distance so that he will be back at home at the end of Day N.

Constraints

1 ≦ | S | ≦ 1000

S consists of the letters N, W, S, E.

Input

The input is given from Standard Input in the following format:

S

Output

Print Yes if it is possible to set each day's travel distance so that he will be back at home at the end of Day N. Otherwise, print No.

Sample Input 1

SENW

Sample Output 1

Yes

If Snuke travels a distance of 1 on each day, he will be back at home at the end of day 4.

Sample Input 2

NSNNSNSN

Sample Output 2

Yes

Sample Input 3

NNEW

Sample Output 3

No

Sample Input 4

W

Sample Output 4

No

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;

// this is not good for reading double values.
public class Main {
	static long m = 100000007;

	public static void main(String[] args) throws IOException {
		Reader r = new Reader();
		PrintWriter o = new PrintWriter(System.out, false);
		int x = 0;
		int y = 0;
		String s = r.readString();
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			if (c == 'N') {
				y += 1;
			} else if (c == 'E') {
				x += 1;
			} else if (c == 'S') {
				y -= 1;
			} else {
				x -= 1;
			}
		}
		int len = s.length();
		char c = s.charAt(len - 1);
		if (c == 'N') {
			if (x == 0 && y >= 0) {
				o.println("Yes");
			} else {
				o.println("No");
			}
		}
		if (c == 'S') {
			if (x == 0 && y <= 0) {
				o.println("Yes");
			} else {
				o.println("No");
			}
		}
		if (c == 'E') {
			if (y == 0 && x >= 0) {
				o.println("Yes");
			} else {
				o.println("No");
			}
		}
		if (c == 'W') {
			if (y == 0 && x <= 0) {
				o.println("Yes");
			} else {
				o.println("No");
			}
		}
		o.close();
	}

	// pair object x,y
	static class pair {
		@Override
		public int hashCode() {
			final int prime = 31;
			int result = 1;
			result = prime * result + x;
			result = prime * result + y;
			return result;
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			pair other = (pair) obj;
			if (x != other.x)
				return false;
			if (y != other.y)
				return false;
			return true;
		}

		int x, y;

		public pair(int x, int y) {
			this.x = x;
			this.y = y;
		}
	}

	public static long gcd(long a, long b) {
		a = Math.abs(a);
		b = Math.abs(b);
		while (b != 0) {
			long temp = a % b;
			a = b;
			b = temp;
		}
		return a;
	}

	public static int gcd(int a, int b) {
		a = Math.abs(a);
		b = Math.abs(b);
		while (b != 0) {
			int temp = a % b;
			a = b;
			b = temp;
		}
		return a;
	}

	static long[][] modPow(long[][] M, long exp) {
		long[][] result = new long[][] { { 1, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 1 } };
		long[][] pow = M;
		while (exp != 0) {
			if ((exp & 1) == 1) {
				result = multiply(result, pow);
			}
			exp >>>= 1;
			pow = multiply(pow, pow);
		}
		return result;
	}

	static long[][] multiply(long[][] A, long[][] B) {
		long[][] C = new long[4][4];
		for (int i = 0; i < 4; i++) {
			for (int j = 0; j < 4; j++) {
				long value = 0;
				for (int k = 0; k < 4; k++) {
					value += A[i][k] * B[k][j];
				}
				C[i][j] = value % m;
			}
		}
		return C;
	}

	// input/output
	static class Reader {
		final private int BUFFER_SIZE = 1 << 16;
		private DataInputStream din;
		private byte[] buffer;
		private int bufferPointer, bytesRead;

		public Reader() {
			din = new DataInputStream(System.in);
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public Reader(String file_name) throws IOException {
			din = new DataInputStream(new FileInputStream(file_name));
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public final String readString() throws IOException {
			int c = read();
			while (isSpaceChar(c)) {
				c = read();
			}
			StringBuilder res = new StringBuilder();
			do {
				res.append((char) c);
				c = read();
			} while (!isSpaceChar(c));
			return res.toString();
		}

		private boolean isSpaceChar(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		public int nextInt() throws IOException {
			int ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (neg)
				return -ret;
			return ret;
		}

		public long nextLong() throws IOException {
			long ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (neg)
				return -ret;
			return ret;
		}

		public double nextDouble() throws IOException {
			double ret = 0, div = 1;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (c == '.')
				while ((c = read()) >= '0' && c <= '9')
					ret += (c - '0') / (div *= 10);
			if (neg)
				return -ret;
			return ret;
		}

		public int[] readIntArray(int size) throws IOException {
			int[] arr = new int[size];
			for (int i = 0; i < size; i++)
				arr[i] = nextInt();
			return arr;
		}

		public long[] readLongArray(int size) throws IOException {
			long[] arr = new long[size];
			for (int i = 0; i < size; i++)
				arr[i] = nextLong();
			return arr;
		}

		private void fillBuffer() throws IOException {
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
			if (bytesRead == -1)
				buffer[0] = -1;
		}

		private byte read() throws IOException {
			if (bufferPointer == bytesRead)
				fillBuffer();
			return buffer[bufferPointer++];
		}

		public void close() throws IOException {
			if (din == null)
				return;
			din.close();
		}
	}
}