#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define maxn 100005
#define maxm 200005
#define INF 1234567890
#define eps 1e-15
#define p 1000000007
const double pi=acos(-1);
template<class T>inline bool read(T &x)
{
    x=0;register char c=getchar();register bool f=0;
    while(!isdigit(c)){if(c==EOF)return false;f^=c=='-',c=getchar();}
    while(isdigit(c))x=(x<<3)+(x<<1)+(c^48),c=getchar();
    if(f)x=-x;
    return true;
}
template<class T>inline bool reads(T &x)
{
    x="";register char c=getchar();
    while(c==' '||c=='\n'||c=='\r'||c=='\t')c=getchar();
    if(c==EOF)return false;
    while(c!=' '&&c!='\n'&&c!='\r'&&c!='\t'&&c!=EOF)x+=c,c=getchar();
    return true;
}
template<class T>inline void print(T x)
{
    if(x<0)putchar('-'),x=-x;
    if(x>9)print(x/10);
    putchar(x%10^48);
}
template<class T>inline void print(T x,char c){print(x),putchar(c);}
template<class T,class ...S>inline bool read(T &x,S &...y){return read(x)&&read(y...);}
ll T,n,a,b;
string s;
int main()
{
    read(T);
    while(T--)
    {
        read(n);
        a=b=0;
        reads(s);
        bool flag=0;
        if(n%3)
        {
            cout<<"NO"<<endl;
            continue;
        }
        for(ll i=0;i<n;i++)
        {
            if(s[i]=='M')b++;
            else a++;
            if(b>a)
            {
                flag=1;
                break;
            }
        }
        if(a!=2*b)flag=1;
        a=b=0;
        for(ll i=n-1;i>=0;i--)
        {
            if(s[i]=='M')b++;
            else a++;
            if(b>a)
            {
                flag=1;
                break;
            }
        }
        if(a!=2*b)flag=1;
        if(flag)cout<<"NO"<<endl;
        else cout<<"YES"<<endl;
    }
    return 0;
}
