#pragma GCC optimize("Ofast,unroll-loops")
#include<bits/stdc++.h>
#define int   long long
#define ll long long
#define down cout<<'\n';
#define debug cout<<" cucuucucuuu",down
#define NHP     ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe  int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define mask(k) (1<<k)
#define mp make_pair
#define checktime   cerr << (double)clock() / CLOCKS_PER_SEC * 1000  << " ms";
using namespace std;
#define getchar_unlocked getchar

inline int scan()
{
    char c = getchar_unlocked();
    int x = 0;
    while (c < '0' || c > '9')
    {
        c = getchar_unlocked();
    }
    while (c >= '0' && c <= '9')
    {
        x = (x << 1) + (x << 3) + c - '0';
        c = getchar_unlocked();
    }
    return x;
}
void phongbeo();
const int inf = 1e18;
const ll mod2 = 1e9+7;
const int  mod1 = 998244353;
const ll base=67;
int add(int x,int y)
{
    if(x+y>=mod2) x-=mod2;
    if(x+y<0)x+=mod2;
    return x+y;
}
struct icd
{
    long double a;
    int b;
};
struct ib
{
    double a;
    int b;
};
struct ic
{
    ll a;
    int  b, c;
};
struct id
{
    int a, b, c, d;
};
struct ie
{
    int a, b, c, d, e;

};
int n, m, s1, s2, s4, s3, sf, k, s5, s6, mx, s7, s8, s9, mx2, res, dem2 = 0, dem = 0, s33, dem3, dem4, mid, l2, r2, center;
int  i, s10, s12,k1,k2,k3,s11,lim,w,l,r ;
int kk;
int el = 19;
main()
{
    if(fopen(task".inp","r"))
    {
        fin(task);
        fou(task);
    }
    NHP
    /// cin>>s1;
    // modwwe
    phongbeo();
//   checktime
}
int a[100007];
int c[100007][2];
int suf[100007][2];
int pre[100007][2];
void phongbeo()
{
    cin>>n;
 for(int i=1;i<=n;i++)
 {
     ///j=1
     ///o=2
     ///i=3
      char s;
       cin>>s;
        if(s=='J')a[i]=1;
        else if(s=='O')a[i]=2;
        else a[i]=3;
 }
  for(int i=n;i>=1;--i)
  {
      suf[i][0]+=suf[i+1][0];
      suf[i][1]+=suf[i+1][1];
  if(a[i]==3)suf[i][0]++;
  else if(a[i]==2)suf[i][1]+=suf[i][0];
  else s4+=suf[i][1];
  }
 for(int i=1;i<=n;i++)
 {
     pre[i][0]+=pre[i-1][0];
     pre[i][1]+=pre[i-1][1];
   if(a[i]==1) pre[i][0]++;
   else if(a[i]==2) pre[i][1]+=pre[i][0];
 }
s5=0;
for(int i=0;i<=n;i++)
{
    s5=max({s5,pre[i][0]*suf[i+1][0],pre[i][1],suf[i+1][1]});
}
cout<<s4+s5;
}