You can not just take the file and send it. When Polycarp trying to send a file in the social network "Codehorses", he encountered an unexpected problem. If the name of the file contains three or more "x" (lowercase Latin letters "x") in a row, the system considers that the file content does not correspond to the social network topic. In this case, the file is not sent and an error message is displayed.

Determine the minimum number of characters to remove from the file name so after that the name does not contain "xxx" as a substring. Print 0 if the file name does not initially contain a forbidden substring "xxx".

You can delete characters in arbitrary positions (not necessarily consecutive). If you delete a character, then the length of a string is reduced by 1. For example, if you delete the character in the position 2 from the string "exxxii", then the resulting string is "exxii".

Input

The first line contains integer n (3 ≤ n ≤ 100) — the length of the file name.

The second line contains a string of length n consisting of lowercase Latin letters only — the file name.

Output

Print the minimum number of characters to remove from the file name so after that the name does not contain "xxx" as a substring. If initially the file name dost not contain a forbidden substring "xxx", print 0.

Examples

Input

6
xxxiii


Output

1


Input

5
xxoxx


Output

0


Input

10
xxxxxxxxxx


Output

8

Note

In the first example Polycarp tried to send a file with name contains number 33, written in Roman numerals. But he can not just send the file, because it name contains three letters "x" in a row. To send the file he needs to remove any one of this letters.
import javax.print.attribute.standard.PrinterMessageFromOperator;
import java.io.*;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.*;
public class Main {
    public static void main(String[] args) throws Exception {
        new Main().run();}

    static int groups = 0;
    static int[] fa;
    static int[] sz;

    static void init1(int n) {
        groups = n;
        fa = new int[n];
        for (int i = 1; i < n; ++i) {
            fa[i] = i;
        }
        sz = new int[n];
        Arrays.fill(sz, 1);
    }

    static int root(int p) {
        while (p != fa[p]) {
            fa[p] = fa[fa[p]];
            p = fa[p];
        }
        return p;
    }

    static void combine(int p, int q) {
        int i = root(p);
        int j = root(q);
        if (i == j) {
            return;
        }
        if (sz[i] < sz[j]) {
            fa[i] = j;
            sz[j] += sz[i];
        } else {
            fa[j] = i;
            sz[i] += sz[j];
        }
        groups--;
    }


    public static String roundS(double result, int scale){
        String fmt = String.format("%%.%df", scale);
        return String.format(fmt, result);
    }

    int[] unique(int a[]){
        int p = 1;
        for(int i=1;i<a.length;++i){
            if(a[i]!=a[i-1]){
                a[p++] = a[i];
            }
        }
        return Arrays.copyOf(a,p);
    }
    public static int eq_bigger(int[] a, int key) {
        return eq_bigger(a,0,a.length,key);
    }

    public static int eq_bigger(int[] a, int lo, int hi,
                                int key) {
        while (lo < hi) {
            int mid = (lo + hi) >>> 1;
            if (a[mid] < key) {
                lo = mid + 1;
            }else {
                hi = mid;
            }
        }
        return lo;
    }

    public static int bigger(int[] a, int key) {
        return bigger(a,0,a.length,key);
    }

    public static int bigger(int[] a, int lo, int hi,
                             int key) {
        while (lo < hi) {
            int mid = (lo + hi) >>> 1;
            if (a[mid] > key) {
                hi = mid;
            }else {
                lo = mid+1;
            }
        }
        return lo;
    }




    void solve() {

        //N , M , K , a , b , c , d . 其中N , M是矩阵的行列数；K 是上锁的房间数目，(a, b)是起始位置，(c, d)是出口位置


//        int n = ni();
//        int m = ni();
//        int k = ni();
//        int a = ni();
//        int b = ni();
//        int c = ni();
//        int d = ni();
//
//
//        char cc[][] = nm(n,m);
//        char keys[][] = new char[n][m];
//
//        char ky = 'a';
//        for(int i=0;i<k;++i){
//            int x = ni();
//            int y = ni();
//            keys[x][y] = ky;
//            ky++;
//        }
//        int f1[] = {a,b,0};
//
//        int dd[][] = {{0,1},{0,-1},{1,0},{-1,0}};
//
//        Queue<int[]> q =  new LinkedList<>();
//        q.offer(f1);
//        int ts = 1;
//
//        boolean vis[][][] = new boolean[n][m][33];
//
//        while(q.size()>0){
//            int sz = q.size();
//            while(sz-->0) {
//                int cur[] = q.poll();
//                vis[cur[0]][cur[1]][cur[2]] = true;
//
//                int x = cur[0];
//                int y = cur[1];
//
//                for (int u[] : dd) {
//                       int lx = x +  u[0];
//                       int ly = y +  u[1];
//                       if (lx >= 0 && ly >= 0 && lx < n && ly < m && (cc[lx][ly] != '#')&&!vis[lx][ly][cur[2]]){
//                            char ck =cc[lx][ly];
//                            if(ck=='.'){
//                                if(lx==c&&ly==d){
//                                    println(ts); return;
//                                }
//                                if(keys[lx][ly]>='a'&&keys[lx][ly]<='z') {
//                                    int cao = cur[2] | (1 << (keys[lx][ly] - 'a'));
//                                    q.offer(new int[]{lx, ly, cao});
//                                    vis[lx][ly][cao] = true;
//                                }else {
//
//                                    q.offer(new int[]{lx, ly, cur[2]});
//                                }
//
//                            }else if(ck>='A'&&ck<='Z'){
//                                int g = 1<<(ck-'A');
//                                if((g&cur[2])>0){
//                                    if(lx==c&&ly==d){
//                                        println(ts); return;
//                                    }
//                                    if(keys[lx][ly]>='a'&&keys[lx][ly]<='z') {
//
//                                        int cao = cur[2] | (1 << (keys[lx][ly] - 'a'));
//                                        q.offer(new int[]{lx, ly, cao});
//                                        vis[lx][ly][cao] = true;;
//                                    }else {
//
//                                        q.offer(new int[]{lx, ly, cur[2]});
//                                    }
//                                }
//                            }
//                       }
//                }
//
//                }
//            ts++;
//        }
//        println(-1);




//        int n = ni();
//
//        HashSet<String> st = new HashSet<>();
//        HashMap<String,Integer> mp = new HashMap<>();
//
//
//        for(int i=0;i<n;++i){
//            String s  = ns();
//            int id= 1;
//            if(mp.containsKey(s)){
//                int u = mp.get(s);
//                id = u;
//
//            }
//
//            if(st.contains(s)) {
//
//                while (true) {
//                    String ts = s + id;
//                    if (!st.contains(ts)) {
//                        s = ts;
//                        break;
//                    }
//                    id++;
//                }
//                mp.put(s,id+1);
//            }else{
//                mp.put(s,1);
//            }
//            println(s);
//            st.add(s);
//
//        }

//        int t = ni();
//
//        for(int i=0;i<t;++i){
//            int n = ni();
//            long w[] = nal(n);
//
//            Map<Long,Long> mp = new HashMap<>();
//            PriorityQueue<long[]> q =new PriorityQueue<>((xx,xy)->{return Long.compare(xx[0],xy[0]);});
//
//            for(int j=0;j<n;++j){
//                q.offer(new long[]{w[j],0});
//                mp.put(w[j],mp.getOrDefault(w[j],0L)+1L);
//            }
//
//            while(q.size()>=2){
//                long f[] = q.poll();
//                long y1 = f[1];
//                if(y1==0){
//                    y1 = mp.get(f[0]);
//                    if(y1==1){
//                        mp.remove(f[0]);
//                    }else{
//                        mp.put(f[0],y1-1);
//                    }
//                }
//                long g[] = q.poll();
//                long y2 = g[1];
//                if(y2==0){
//                    y2 = mp.get(g[0]);
//                    if(y2==1){
//                        mp.remove(g[0]);
//                    }else{
//                        mp.put(g[0],y2-1);
//                    }
//                }
//                q.offer(new long[]{f[0]+g[0],2L*y1*y2});
//
//            }
//            long r[] = q.poll();
//            println(r[1]);
//
//
//
//
//        }
        //  int o= 9*8*7*6;
        //  println(o);


//       int t = ni();
//       for(int i=0;i<t;++i){
//           long a = nl();
//           int k  = ni();
//           if(k==1){
//               println(a);
//               continue;
//           }
//
//           int f = (int)(a%10L);
//           int s = 1;
//           int j = 0;
//           for(;j<30;j+=2){
//               int u = f-j;
//               if(u<0){
//                   u = 10+u;
//               }
//               s = u*s;
//               s = s%10;
//               if(s==k){
//                   break;
//               }
//           }
//
//           if(s==k) {
//               println(a - j - 2);
//           }else{
//               println(-1);
//           }
//
//
//
//
//       }

//     int m = ni();
//     h = new int[n];
//     to = new int[2*(n-1)];
//     ne = new int[2*(n-1)];
//     wt = new int[2*(n-1)];
//
//     for(int i=0;i<n-1;++i){
//         int u = ni()-1;
//         int v = ni()-1;
//
//     }
        //  long a[] = nal(n);


//        int n = ni();
//        int k = ni();
//        t1 = new long[200002];
//
//        int p[][] = new int[n][3];
//
//        for(int i=0;i<n;++i){
//            p[i][0]  = ni();
//            p[i][1]  = ni();
//            p[i][2]  = i+1;
//        }
//        Arrays.sort(p, new Comparator<int[]>() {
//            @Override
//            public int compare(int[] x, int[] y) {
//                if(x[1]!=y[1]){
//                    return Integer.compare(x[1],y[1]);
//                }
//                return Integer.compare(y[0], x[0]);
//            }
//        });
//
//        for(int i=0;i<n;++i){
//            int ck = p[i][0];
//
//        }


        int n  =ni();

        String s =ns();
        int num = 0;
        int si =0;
        for(int i=0;i<n;++i){
            char c = s.charAt(i);
            if(c=='x'){
                num++;
            }

            if(c!='x'||i==n-1){
                si += Math.max(0,num-2);
                num = 0;
            }

        }
        println(si);









    }






    int cnt[][];
    long dp[][];


    int h[];
    int to[];
    int ne[];
    int ct = 0;

    int x[][];
    void dfs(int rt, int fa, int cur){
        x[rt][cur] = fa;
        cnt[rt][cur] = 1;
        for(int i=h[cur];i!=-1;i=ne[i]){
            int go = to[i];
            if(go==fa) continue;
            dfs(rt, cur, go);
            cnt[rt][cur] += cnt[rt][go];
        }
    }


//    int []h,to,ne,wt;

    long t1[];
    //    long t2[];
    void update(long[] t,int i,long v){
        for(;i<t.length;i+=(i&-i)){
            t[i] += v;
        }
    }
    long get(long[] t,int i){
        long s = 0;
        for(;i>0;i-=(i&-i)){
            s += t[i];
        }
        return s;
    }

    int equal_bigger(long t[],long v){
        int s=0,p=0;
        for(int i=Integer.numberOfTrailingZeros(Integer.highestOneBit(t.length));i>=0;--i) {
            if(p+(1<<i)< t.length && s + t[p+(1<<i)] < v){
                v -= t[p+(1<<i)];
                p |= 1<<i;
            }
        }
        return p+1;
    }









    static class S{
        int l = 0;
        int r = 0 ;
        long le = 0;
        long ri = 0;
        long tot = 0;
        long all = 0;

        public S(int l,int r) {
            this.l = l;
            this.r = r;
        }
    }

    static S a[];
    static int[] o;

    static void init(int[] f){
        o = f;
        int len = o.length;
        a = new S[len*4];
        build(1,0,len-1);
    }

    static void build(int num,int l,int r){
        S cur = new S(l,r);
        if(l==r){
            a[num] = cur;
            return;
        }else{
            int m = (l+r)>>1;
            int le = num<<1;
            int ri = le|1;
            build(le, l,m);
            build(ri, m+1,r);
            a[num] = cur;
            pushup(num, le, ri);
        }
    }



    //    static int query(int num,int l,int r){
//
//        if(a[num].l>=l&&a[num].r<=r){
//            return a[num].tot;
//        }else{
//            int m = (a[num].l+a[num].r)>>1;
//            int le = num<<1;
//            int ri = le|1;
//            pushdown(num, le, ri);
//            int ma = 1;
//            int mi = 100000001;
//            if(l<=m) {
//                int r1 = query(le, l, r);
//                ma = ma*r1;
//
//            }
//            if(r>m){
//                int r2 = query(ri, l, r);
//                ma = ma*r2;
//            }
//            return ma;
//        }
//    }
    static long dd = 10007;
    static void update(int num,int l,long v){
        if(a[num].l==a[num].r){
            a[num].le = v%dd;
            a[num].ri = v%dd;
            a[num].all = v%dd;
            a[num].tot = v%dd;
        }else{
            int m = (a[num].l+a[num].r)>>1;
            int le = num<<1;
            int ri = le|1;
            pushdown(num, le, ri);
            if(l<=m){
                update(le,l,v);
            }
            if(l>m){
                update(ri,l,v);
            }
            pushup(num,le,ri);
        }
    }

    static void pushup(int num,int le,int ri){
        a[num].all = (a[le].all*a[ri].all)%dd;
        a[num].le = (a[le].le + a[le].all*a[ri].le)%dd;
        a[num].ri = (a[ri].ri + a[ri].all*a[le].ri)%dd;
        a[num].tot = (a[le].tot + a[ri].tot + a[le].ri*a[ri].le)%dd;


        //a[num].res[1] = Math.min(a[le].res[1],a[ri].res[1]);
    }
    static void pushdown(int num,int le,int ri){

    }


    int gcd(int a,int b){ return b==0?a: gcd(b,a%b);}
    InputStream is;PrintWriter out;
    void run() throws Exception {is = System.in;out = new PrintWriter(System.out);solve();out.flush();}
    private byte[] inbuf = new byte[2];
    public int lenbuf = 0, ptrbuf = 0;
    private int readByte() {
        if (lenbuf == -1) throw new InputMismatchException();
        if (ptrbuf >= lenbuf) {
            ptrbuf = 0;
            try {lenbuf = is.read(inbuf);} catch (IOException e) {throw new InputMismatchException();}
            if (lenbuf <= 0) return -1;
        }
        return inbuf[ptrbuf++];}
    private boolean isSpaceChar(int c) {return !(c >= 33 && c <= 126);}
    private int skip() {int b;while((b = readByte()) != -1 && isSpaceChar(b));return b;}
    private double nd() {return Double.parseDouble(ns());}
    private char nc() {return (char) skip();}
    private char ncc() {int b;while((b = readByte()) != -1 && !(b >= 32 && b <= 126));return (char)b;}
    private String ns() {int b = skip();StringBuilder sb = new StringBuilder();
        while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);b = readByte(); }
        return sb.toString();}
    private char[] ns(int n) {char[] buf = new char[n];int b = skip(), p = 0;
        while (p < n && !(isSpaceChar(b))) { buf[p++] = (char) b;b = readByte(); }
        return n == p ? buf : Arrays.copyOf(buf, p);}
    private String nline() {int b = skip();StringBuilder sb = new StringBuilder();
        while (!isSpaceChar(b) || b == ' ') { sb.appendCodePoint(b);b = readByte(); }
        return sb.toString();}
    private char[][] nm(int n, int m) {char[][] a = new char[n][];for (int i = 0; i < n; i++) a[i] = ns(m);return a;}
    private int[] na(int n) {int[] a = new int[n];for (int i = 0; i < n; i++) a[i] = ni();return a;}
    private long[] nal(int n) { long[] a = new long[n];for (int i = 0; i < n; i++) a[i] = nl();return a;}
    private int ni() { int num = 0, b; boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')){};
        if (b == '-') { minus = true; b = readByte(); }
        while (true) {
            if (b >= '0' && b <= '9') num = (num << 3) + (num << 1) + (b - '0');
            else return minus ? -num : num;
            b = readByte();}}
    private long nl() { long num = 0; int b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')){};
        if (b == '-') { minus = true; b = readByte(); }
        while (true) {
            if (b >= '0' && b <= '9')  num = num * 10 + (b - '0');
            else return minus ? -num : num;
            b = readByte();}}
    void print(Object obj){out.print(obj);}
    void println(Object obj){out.println(obj);}
    void println(){out.println();}
}