Vova has won n trophies in different competitions. Each trophy is either golden or silver. The trophies are arranged in a row.

The beauty of the arrangement is the length of the longest subsegment consisting of golden trophies. Vova wants to swap two trophies (not necessarily adjacent ones) to make the arrangement as beautiful as possible — that means, to maximize the length of the longest such subsegment.

Help Vova! Tell him the maximum possible beauty of the arrangement if he is allowed to do at most one swap.

Input

The first line contains one integer n (2 ≤ n ≤ 10^5) — the number of trophies.

The second line contains n characters, each of them is either G or S. If the i-th character is G, then the i-th trophy is a golden one, otherwise it's a silver trophy. 

Output

Print the maximum possible length of a subsegment of golden trophies, if Vova is allowed to do at most one swap.

Examples

Input


10
GGGSGGGSGG


Output


7


Input


4
GGGG


Output


4


Input


3
SSS


Output


0

Note

In the first example Vova has to swap trophies with indices 4 and 10. Thus he will obtain the sequence "GGGGGGGSGS", the length of the longest subsegment of golden trophies is 7. 

In the second example Vova can make no swaps at all. The length of the longest subsegment of golden trophies in the sequence is 4. 

In the third example Vova cannot do anything to make the length of the longest subsegment of golden trophies in the sequence greater than 0.
import java.util.*;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.zip.ZipEntry;

import javax.imageio.stream.MemoryCacheImageInputStream;
import javax.security.auth.Subject;
import javax.security.auth.kerberos.KerberosKey;
import javax.swing.plaf.basic.BasicScrollPaneUI.HSBChangeListener;
import javax.swing.text.StyledEditorKit.BoldAction;
import javax.tools.JavaCompiler;
import javax.xml.bind.SchemaOutputResolver;
import javax.xml.crypto.dsig.spec.DigestMethodParameterSpec;
 
import org.omg.CORBA.TRANSACTION_MODE;
import org.omg.IOP.TAG_CODE_SETS;
 
import java.awt.font.GraphicAttribute;
import java.io.*;
import java.nio.channels.AcceptPendingException;
import java.rmi.server.RMIClassLoader;
import java.security.spec.DSAGenParameterSpec;
import java.sql.PseudoColumnUsage;
import java.time.Period;

   public class codeforces {
	 
    public static void main(String[] args) throws Exception {
 int n=sc.nextInt();
 String S=sc.next();
 int g=0;
 int s=0;
 boolean gold=true;
 ArrayList<Integer>arr=new ArrayList<Integer>();
 int goool=0;
 for(int i=0;i<n;i++) {
	 if(S.charAt(i)=='G'&&gold) {
		 g++;
	 }else {
		if(S.charAt(i)=='S'&&!gold) {
			s++;
		}else {
			if(gold) {
				gold=false;
				arr.add(g);
				if(g!=0) {
					goool++;
				}
				g=0;
				s++;
			}else {
				gold=true;
				arr.add(s);
				g++;
				s=0;
			}
		}
	}
 }if(gold) {
		gold=false;
		arr.add(g);
		if(g!=0) {
			goool++;
		}
		g=0;
		s++;
	}else {
		gold=true;
		arr.add(s);
		g++;
		s=0;
	}
 arr.add(0);
 arr.add(0);
 arr.add(0);
 long ans=0;
 
   for(int i=0;i<arr.size();i++) {
	   if(i%2==1&&arr.get(i)==1) {
		   if(goool>2) {
		   ans=Math.max(ans, arr.get(i-1)+arr.get(i+1)+1);
		   }else{
			ans=Math.max(ans, arr.get(i-1)+arr.get(i+1));
		}
	   }else if(i%2==0) {
		   if(goool>1) {
		   ans=Math.max(ans,arr.get(i)+1);
		   }
		   else {
			   ans=Math.max(ans,arr.get(i));
		}
	}
   }
//   pw.println(arr);
   pw.print(ans);
    	
    	
    	
    	
    	
    	
    	
       pw.close();
    }
 
	static class Scanner {
		StringTokenizer st;
		BufferedReader br;
 
		public Scanner(InputStream s) {
			br = new BufferedReader(new InputStreamReader(s));
		}
 
		public Scanner(FileReader r) {
			br = new BufferedReader(r);
		}
 
		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}
 
		public int nextInt() throws IOException {
			return Integer.parseInt(next());
		}
 
		public long nextLong() throws IOException {
			return Long.parseLong(next());
		}
 
		public String nextLine() throws IOException {
			return br.readLine();
		}
 
		public double nextDouble() throws IOException {
			String x = next();
			StringBuilder sb = new StringBuilder("0");
			double res = 0, f = 1;
			boolean dec = false, neg = false;
			int start = 0;
			if (x.charAt(0) == '-') {
				neg = true;
				start++;
			}
			for (int i = start; i < x.length(); i++)
				if (x.charAt(i) == '.') {
					res = Long.parseLong(sb.toString());
					sb = new StringBuilder("0");
					dec = true;
				} else {
					sb.append(x.charAt(i));
					if (dec)
						f *= 10;
				}
			res += Long.parseLong(sb.toString()) / f;
			return res * (neg ? -1 : 1);
		}
		public long[] nextlongArray(int n) throws IOException {
            long[] a = new long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }
		public Long[] nextLongArray(int n) throws IOException {
            Long[] a = new Long[n];
            for (int i = 0; i < n; i++)
                a[i] = nextLong();
            return a;
        }
		public int[] nextIntArray(int n) throws IOException {
            int[] a = new int[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }
		public Integer[] nextIntegerArray(int n) throws IOException {
            Integer[] a = new Integer[n];
            for (int i = 0; i < n; i++)
                a[i] = nextInt();
            return a;
        }
		public boolean ready() throws IOException {
			return br.ready();
		}
 
	}
 
	static class pair implements Comparable<pair> {
		long x;
		long y;
 
		public pair(long x, long y) {
			this.x = x;
			this.y = y;
		}
 
		public String toString() {
			return x + " " + y;
		}
		public boolean equals(Object o) {
            if (o instanceof pair) {
                pair p = (pair)o;
                return p.x == x && p.y == y;
            }
            return false;
        }
        public int hashCode() {
            return new Double(x).hashCode() * 31 + new Double(y).hashCode();
        }
        public int compareTo(pair other) {
        	if(this.x==other.x) {
        		return Long.compare(this.y, other.y);
        	}
			return Long.compare(this.x, other.x);
		}
	}
 
	static class tuble implements Comparable<tuble> {
		int x;
		int y;
		int z;
 
		public tuble(int x, int y, int z) {
			this.x = x;
			this.y = y;
			this.z = z;
		}
 
		public String toString() {
			return x + " " + y + " " + z;
		}
 
		public int compareTo(tuble other) {
			if (this.x == other.x) {
				if(this.y==other.y) {
					return this.z - other.z;
				}
				return this.y - other.y;
			} else {
				return this.x - other.x;
			}
		}
	}
 
	public static long GCD(long a, long b) {
		if (b == 0)
			return a;
		if (a == 0)
			return b;
		return (a > b) ? GCD(a % b, b) : GCD(a, b % a);
	}
 
	public static long LCM(long a, long b) {
		return a * b / GCD(a, b);
	}
 
	static long Pow(long a, long e, long mod) // O(log e)
	{
		a %= mod;
		long res = 1l;
		while (e > 0) {
			if ((e & 1) == 1)
				res = (res * a) % mod;
			a = (a * a) % mod;
			e >>= 1l;
		}
		return res;
	}
   public static long modinverse(long a,long mod) {
	   return Pow(a, mod-2, mod);
   }
	static long nc(int n, int r) {
		if (n < r)
			return 0;
		long v = fac[n];
		v *= Pow(fac[r], mod - 2, mod);
		v %= mod;
		v *= Pow(fac[n - r], mod - 2, mod);
		v %= mod;
		return v;
	}
 
	public static boolean isprime(long a) {
		if (a == 0 || a == 1) {
			return false;
		}
		if (a == 2) {
			return true;
		}
		for (int i = 2; i < Math.sqrt(a) + 1; i++) {
			if (a % i == 0) {
				return false;
			}
		}
		return true;
	}
 
	public static boolean isPal(String s) {
		boolean t = true;
		for (int i = 0; i < s.length(); i++) {
			if (s.charAt(i) != s.charAt(s.length() - 1 - i)) {
				t = false;
				break;
			}
		}
		return t;
	}
 
	public static long RandomPick(long[] a) {
		int n = a.length;
		int r = rn.nextInt(n);
		return a[r];
	}
 
	public static int RandomPick(int[] a) {
		int n = a.length;
		int r = rn.nextInt(n);
		return a[r];
	}
 static class hash {
	 int[]HashsArray;
	 boolean reverse;
	 int prelen;
	public  hash(String s, boolean r) {
		prelen = s.length();
		reverse=r;
		HashsArray = new int[prelen + 1];
		if (HashsArrayInd == 0) {
			int[] mods = { 1173017693, 1173038827, 1173069731, 1173086977, 1173089783, 1173092147, 1173107093,
					1173114391, 1173132347, 1173144367, 1173150103, 1173152611, 1173163993, 1173174127, 1173204679,
					1173237343, 1173252107, 1173253331, 1173255653, 1173260183, 1173262943, 1173265439, 1173279091,
					1173285331, 1173286771, 1173288593, 1173298123, 1173302129, 1173308827, 1173310451, 1173312383,
					1173313571, 1173324371, 1173361529, 1173385729, 1173387217, 1173387361, 1173420799, 1173421499,
					1173423077, 1173428083, 1173442159, 1173445549, 1173451681, 1173453299, 1173454729, 1173458401,
					1173459491, 1173464177, 1173468943, 1173470041, 1173477947, 1173500677, 1173507869, 1173522919,
					1173537359, 1173605003, 1173610253, 1173632671, 1173653623, 1173665447, 1173675577, 1173675787,
					1173684683, 1173691109, 1173696907, 1173705257, 1173705523, 1173725389, 1173727601, 1173741953,
					1173747577, 1173751499, 1173759449, 1173760943, 1173761429, 1173762509, 1173769939, 1173771233,
					1173778937, 1173784637, 1173793289, 1173799607, 1173802823, 1173808003, 1173810919, 1173818311,
					1173819293, 1173828167, 1173846677, 1173848941, 1173853249, 1173858341, 1173891613, 1173894053,
					1173908039, 1173909203, 1173961541, 1173968989, 1173999193};
			mod = RandomPick(mods);
			int[] primes = { 59, 61, 67, 71, 73, 79, 83, 89, 97, 101 };
			prime = RandomPick(primes);
			prepow = new int[1000010];
			prepow[0] = 1;
			for (int i = 1; i < 1000010; i++) {
				prepow[i] = (int) ((1l * prepow[i - 1] * prime) % mod);
				
			}
		}
		if (!reverse) {
 
			for (int i = 0; i < prelen; i++) {
				if (s.charAt(i) >= 'a' && s.charAt(i) <= 'z')
					HashsArray[i + 1] = (int) ((1l * HashsArray[i]
							+ ((1l * s.charAt(i) - 'a' + 1) *prepow[i]) % mod) % mod);
				else
					HashsArray[i + 1] = (int) ((1l * HashsArray[i]
							+ ((1l * s.charAt(i) - 'A' + 27) * prepow[i]) % mod) % mod);
			}
 
		} else {
			
			for (int i = 0; i < prelen; i++) {
				if (s.charAt(i) >= 'a' && s.charAt(i) <= 'z')
					HashsArray[i + 1] = (int) ((1l * HashsArray[i]
							+ ((1l * s.charAt(i) - 'a' + 1) * prepow[1000010 - 1 - i]) % mod) % mod);
				else
					HashsArray[i + 1] = (int) ((1l * HashsArray[i]
							+ ((1l * s.charAt(i) - 'A' + 27) * prepow[1000010 - 1 - i]) % mod) % mod);
			}
 
		}
 
		HashsArrayInd++;
 
	}
 
	public int PHV(int l, int r) {
		if (l > r) {
			return 0;
		}
		int val = (int) ((1l * HashsArray[r] + mod - HashsArray[l - 1]) % mod);
		if (!reverse) {
 
//			val = (int) ((1l * val *  modinverse(prepow[l-1], mod)) % mod);
			val = (int) ((1l * val * prepow[1000010 - l]) % mod);
		} else {
//			val = (int) ((1l * val * modinverse(prepow[prelen-r], mod)) % mod);
			
			val = (int) ((1l * val * prepow[r - 1]) % mod);
		}
		return val;
	}
 }
    public static void genprime(int n) {
    	 boolean prime[] = new boolean[n+1]; 
         for(int i=0;i<n;i++) 
             prime[i] = true; 
           
         for(int p = 2; p*p <=n; p++) 
         { 
             if(prime[p] == true) 
             { 
                 for(int i = p*p; i <= n; i += p) 
                     prime[i] = false; 
             } 
         } 
         for(int i = 2; i <= n; i++) 
         { 
             if(prime[i] == true) {
                primes.put(i,primes.size());
                primes2.put(primes2.size(),i);
             }
             
         }
    }
   
   
    public static long LSB(long x) {
		return x&-x;
	}
	static class fenwick {
		long[] arr;
		public fenwick(Integer[] a) {
			arr=new long[a.length+1];
			for(int i=1;i<=a.length;i++) {
				arr[i]+=a[i-1];
				if(i+LSB(i)<=a.length) {
					arr[(int) (i+LSB(i))]+=arr[i];
				}
			}
		}
		public fenwick(int[] a) {
			arr=new long[a.length+1];
			for(int i=1;i<=a.length;i++) {
				arr[i]+=a[i-1];
				if(i+LSB(i)<=a.length) {
					arr[(int) (i+LSB(i))]+=arr[i];
				}
			}
		}public fenwick(long[] a) {
			arr=new long[a.length+1];
			for(int i=1;i<=a.length;i++) {
				arr[i]+=a[i];
				if(i+LSB(i)<=a.length) {
					arr[(int) (i+LSB(i))]+=arr[i];
				}
			}
		}
		public void update(int ind,long x) {
			int i=ind;
			while(i<arr.length) {
				arr[i]+=x;
				i+=LSB(i);
			}
		}
		public long PrefixSum(int ind) {
			long sum=0;
			int i=ind;
			while(i>0) {
				sum+=arr[i];
				i=(int) (i-LSB(i));
			}
			return sum;
		}
		public long RangeQuerey(int l,int r) {
			return  this.PrefixSum(r+1)-this.PrefixSum(l);
		}
		public long maxConsecutiveValue(int k) {
			long max=Long.MIN_VALUE;
			for(int i=k-1;i<arr.length-1;i++) {
				
				max= Math.max(max,  this.RangeQuerey(i-k+1, i));
				
			}
			return max;
		}
		public long minConsecutiveValue(int k) {
			long min=Long.MAX_VALUE;
			
			for(int i=k-1;i<arr.length-1;i++) {
				
				min= Math.min(min,  this.RangeQuerey(i-k+1, i));
				
			}
			return min;
		}
		public long value(int ind) {
			return arr[ind];
		}
	}
	static void sieveLinear(int N)
	{
		ArrayList<Integer> primes = new ArrayList<Integer>();
		lp = new int[N + 1];								//lp[i] = least prime divisor of i
		for(int i = 2; i <= N; ++i)
		{
			if(lp[i] == 0)
			{
				primes.add(i);
				lp[i] = i;
			}
			int curLP = lp[i];
			for(int p: primes)//all primes smaller than or equal my lowest prime divisor
				if(p > curLP || p * 1l * i > N)
					break;
				else
					lp[p * i] = p;
		}
	}
	public static void primefactorization(int n) {
		int x=n;
	while(x>1) {
		int lowestDivisor=lp[x];
		while(x%lowestDivisor==0) {
			primefactors.add(lowestDivisor);
			x/=lowestDivisor;
		}
	}
	}
	public static class SuffixArray {

		int[] SA;
		int[] AS;
		String SS;
		public SuffixArray(String S)					//has a terminating character (e.g. '$')
		{
			SS=S;
			char[] s=new char[S.length()+1];
			for(int i=0;i<S.length();i++) {
				s[i]=S.charAt(i);
			}
			s[S.length()]='$';
			int n = s.length, RA[] = new int[n];
			SA = new int[n];
			
			for(int i = 0; i < n; ++i) { RA[i] = s[i]; SA[i] = i; }
			
			for(int k = 1; k < n; k <<= 1)
			{
				sort(SA, RA, n, k);
				sort(SA, RA, n, 0);
				int[] tmp = new int[n];

				for(int i = 1, r = 0, s1 = SA[0], s2; i < n; ++i)
				{
					s2 = SA[i];
					tmp[s2] = RA[s1] == RA[s2] && RA[s1 + k] == RA[s2 + k] ? r : ++r;
					s1 = s2;
				}
				for(int i = 0; i < n; ++i)
					RA[i] = tmp[i];
				
				if(RA[SA[n-1]] == n - 1)
					break;
			}
			AS=new int[SA.length];
			for(int i=0;i<SA.length;i++) {
				AS[SA[i]]=i;
			}
		}
		public String toString() {
			
			return Arrays.toString(SA);
		}
		public int get(int n) {
			return SA[n];
		}
		public int Substring(String s) {  // log(n)*|s|
			int low=0;
			int high=SA.length;
			int mid=(low+high)/2;
			int ind=-1;
			
			while(low<high-1) {
				
				if(SS.length()-SA[mid]<s.length()) {
				
					boolean less=false;
					for(int i=SA[mid];i<SS.length();i++) {
						if(SS.charAt(i)>s.charAt(i-SA[mid])) {
							less=true;
							break;
						}
						if(SS.charAt(i)<s.charAt(i-SA[mid])) {
							less=false;
							break;
						}
					}
					if(!less) {
						low=mid;
					}else {
						high=mid;
					}
				}else {
					boolean less=true;
					boolean equal=true;
					for(int i=SA[mid];i<SA[mid]+s.length();i++) {
						if(SS.charAt(i)<s.charAt(i-SA[mid])&&equal) {
							less=false;
							equal=false;
							break;
						}
						if(SS.charAt(i)!=s.charAt(i-SA[mid])){
							equal=false;
						}
					}
					if(equal) {
						ind=SA[mid];
					}
					if(!less) {
						low=mid;
					}else {
						high=mid;
					}
				}
				
				
				mid=(low+high)/2;
			}
			return ind;
		}
		public int LastSubstring(String s) {  // log(n)*|s|
			int low=0;
			int high=SA.length;
			int mid=(low+high)/2;
			int ind=-1;
			
			while(low<high-1) {
				
				if(SS.length()-SA[mid]<s.length()) {
				
					boolean less=true;
					for(int i=SA[mid];i<SS.length();i++) {
						if(SS.charAt(i)<s.charAt(i-SA[mid])) {
							break;
						}
						if(SS.charAt(i)>s.charAt(i-SA[mid])) {
							less=false;
							break;
						}
					}
					if(less) {
						low=mid;
					}else {
						high=mid;
					}
				}else {
					boolean less=true;
					boolean equal=true;
					for(int i=SA[mid];i<SA[mid]+s.length();i++) {
						if(SS.charAt(i)>s.charAt(i-SA[mid])&&equal) {
							less=false;
							equal=false;
							break;
						}
						if(SS.charAt(i)!=s.charAt(i-SA[mid])){
							equal=false;
						}
					}
					if(equal) {
						ind=SA[mid];
					}
					if(less) {
						low=mid;
					}else {
						high=mid;
					}
				}
				
				
				mid=(low+high)/2;
			}
			return ind;
		}
		public int CountSubstring(String s) {
			int z=LastSubstring(s);
			if(z==-1)
				return 0;
			return AS[z]-AS[Substring(s)]+1;
		}
		public void sort(int[] SA, int[] RA, int n, int k)
		{
			int maxi = Math.max(256, n), c[] = new int[maxi];  
			for(int i = 0; i < n; ++i)
				c[i + k < n ? RA[i + k] : 0]++;
			for(int i = 0, sum = 0; i < maxi; ++i)
			{
				int t = c[i];
				c[i] = sum;
				sum += t;
			}
			int[] tmp = new int[n];
			for(int i = 0; i < n; ++i)
			{
				int j = SA[i] + k;
				tmp[c[j < n ? RA[j] : 0]++] = SA[i];
			}
			
			for(int i = 0; i < n; ++i)
				SA[i] = tmp[i];
		}
	}
	static LinkedList<Integer>primefactors=new LinkedList<>();
	static TreeMap<Integer,Integer>primes=new TreeMap<Integer, Integer>();
	static TreeMap<Integer,Integer>primes2=new TreeMap<Integer, Integer>();
	static int[]lp;
    
	
	static int HashsArrayInd = 0;
	static int[] prepow;
	static int prime = 61;
	static long fac[];
	static int mod = 1000000007;
	static Random rn = new Random();
	static Scanner sc = new Scanner(System.in);
	static PrintWriter pw = new PrintWriter(System.out);
}