#include<bits/stdc++.h>   using namespace std;       typedef long long ll;   typedef vector< ll > vl;   typedef vector< vector< ll > > vvl;   #define ff first   #define ss second   #define boost ios_base::sync_with_stdio(false); cin.tie(NULL);   cout.tie(NULL);   #define pb push_back   #define all(c) c.begin(), c.end()   #define tr(c,it) for(auto it=(c).begin(); it!=(c).end(); it++)   #define ref(i,n)    for(i=0;i<n;i++)   #define mp make_pair   #define endl   n    #define MOD 1000000007   ll power(ll a, ll b){//a^b       ll res=1;       a=a%MOD;       while(b>0){           if(b&1){res=(res*a)%MOD;b--;}           a=(a*a)%MOD;           b>>=1;       }       return res;   }   ll fermat_inv(ll y){return power(y,MOD-2);}   ll gcd(ll a, ll b){return (b==0)?a:gcd(b,a%b);}      int main()   {       boost       ll t;       cin>>t;       while(t--)       {           ll n,x=0,y=0,flag=0,m,i;           cin>>n;           string s;           cin>>s;           ref(i,n)           {               if(s[i]== T )                   x++;               else               {                   y++;               }               if(y>x)               {                   flag=1;                   break;               }           }           if(flag==1 || x!=2*y)           {               cout<< NO <<endl;               continue;           }           x=y=flag=0;           for(i=n-1;i>=0;i--)           {               if(s[i]== T )                   x++;               else               {                   y++;               }               if(y>x)               {                   flag=1;                   break;               }           }           if(flag)               cout<< NO <<endl;           else               cout<< YES <<endl;       }       return 0;   }         