Problem:
B: たぬきつね

問題

謎の装置 $M$ があり,この装置に Tanuki と Fox を入れると, 装置から一匹の動物が出てくる（以下, Tanuki を $T$ ,Foxを $F$ とする）.

$M(x, y)$ は,装置 $M$ に $x, y$ の順で動物を入れて出てきた動物を表す.

色々試した結果,以下のことがわかった.

$M(T, T) = T$

$M(T, F) = F$

$M(F, T) = T$

$M(F, F) = T$

あなたは,一列に並んでいる動物たち $P_1, P_2, ... , P_N$ を以下のように装置に入れていった.

$M(....M(M(P_1,P_2), P_3)...., P_N)$

最後に出てくる動物を答えよ.

制約

$2 \leq N \leq 10^{5}$

$P_i$ は $T$ か $F$ の一文字

入力形式

入力は以下の形式で与えられる.

$N$

$P_1\ P_2\ ...\ P_N$

出力

最後に出てくる動物を表す文字 $T$ または $F$ を出力せよ.また,末尾に改行も出力せよ.

サンプル

サンプル入力 1

3
F T T

サンプル出力 1

T

サンプル入力 2

7
F T T F T T F

サンプル出力 2

F

Solution in JAVA (judge verdict: Accepted)

import java.util.*;
import java.util.stream.*;
import java.io.*;
import java.math.*;

public class Main {

	static void solve (FastScanner in, PrintWriter out, Methods ms) {
		
		int n = in.nextInt();
		char ans = animal(in.next().charAt(0), in.next().charAt(0));
		for (int i=0; i<n-2; i++) {
			ans = animal(ans, in.next().charAt(0));
		}
		out.println(ans);
		
	}
	
	static char animal (char a, char b) {
		if (a=='T' && b=='F') return 'F';
		else return 'T';
	}



	public static void main(String[] args) {
		FastScanner in = new FastScanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		Methods ms = new Methods();
		solve(in, out, ms);
		in.close();
		out.close();
	}

	static class Methods {

		public void print (Object... ar) {System.out.println(Arrays.deepToString(ar));}

		public int max (int... ar) {Arrays.sort(ar); return ar[ar.length-1];}

		public int min (int... ar) {Arrays.sort(ar); return ar[0];}

		public long gcd (long a, long b) {return b>0?gcd(b,a%b):a;}

		public long lcm (long a, long b) {return a/gcd(a,b)*b;}

		public long factorial (int i) {
			if (i==1) return 1;
			else return i*factorial(i-1);
		}

		public int manhat (int x1, int y1, int x2, int y2) {
			return Math.abs(x1-x2)+Math.abs(y1-y2);
		}

		public double euclid (double x1, double y1, double x2, double y2) {
			return Math.sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
		}

		public boolean isPrime (int n) {
			if (n==2) return true;
			if (n<2 || n%2==0) return false;
			for (int i=3; i<=Math.sqrt(n); i+=2) if(n%i==0) return false;
			return true;
		}

	}

	static class FastScanner {

		private InputStream in;
		private byte[] buffer = new byte[1024];
		private  int length = 0, p = 0;

		public FastScanner (InputStream stream) {
			in = stream;
		}

		public boolean hasNextByte () {
			if (p < length) return true;
			else {
				p = 0;
				try {length = in.read(buffer);}
				catch (Exception e) {e.printStackTrace();}
				if (length <= 0) return false;
			}
			return true;
		}

		public int readByte () {
			if (hasNextByte() == true) return buffer[p++];
			return -1;
		}

		public boolean isPrintable (int n) {return 33<=n&&n<=126;}

		public void skip () {
			while (hasNextByte() && !isPrintable(buffer[p])) p++;
		}

		public boolean hasNext () {skip(); return hasNextByte();}

		public String next () {
			if (!hasNext()) throw new NoSuchElementException();
			StringBuilder sb = new StringBuilder();
			int t = readByte();
			while (isPrintable(t)) {
				sb.appendCodePoint(t);
				t = readByte();
			}
			return sb.toString();
		}

		public String[] nextArray (int n) {
			String[] ar = new String[n];
			for (int i=0; i<n; i++) ar[i] = next();
			return ar;
		}

		public int nextInt () {return Math.toIntExact(nextLong());}

		public int[] nextIntArray (int n) {
			int[] ar = new int[n];
			for (int i=0; i<n; i++) ar[i] = nextInt();
			return ar;
		}

		public long nextLong () {
			if (!hasNext()) throw new NoSuchElementException();
			boolean minus = false;
			int temp = readByte();
			if (temp == '-') {
				minus = true;
				temp = readByte();
			}
			if (temp<'0' || '9'<temp) throw new NumberFormatException();
			long n = 0;
			while (isPrintable(temp)) {
				if ('0'<=temp && temp<='9') {
					n *= 10;
					n += temp - '0';
				}
				else throw new NumberFormatException();
				temp = readByte();
			}
			return minus? -n : n;
		}

		public long[] nextLongArray (int n) {
			long[] ar = new long[n];
			for (int i=0; i<n; i++) ar[i] = nextLong();
			return ar;
		}

		public double nextDouble () {
			return Double.parseDouble(next());
		}

		public double[] nextDoubleArray (int n) {
			double[] ar = new double[n];
			for (int i=0; i<n; i++) ar[i] = nextDouble();
			return ar;
		}

		public void close () {
			try {in.close();}
			catch(Exception e){}
		}

	}

}