#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;
}
