#include<iostream>

 #include<string>

 #include<algorithm>

 #include<cstdlib>

 #include<cstdio>

 #include<set>

 #include<map>

 #include<vector>

 #include<cstring>

 #include<stack>

 #include<cmath>

 #include<queue>

 #define clc(a,b) memset(a,b,sizeof(a))

 #include <bits/stdc++.h>

 using namespace std;

 #define LL long long

 int main()

 {

     int n;

     int p[][];

     scanf("%d",&n);

     clc(p,);

     for(int i=; i<=n; i++)

     {

         char c;

         int l,r;

         getchar();

         scanf("%c%d%d",&c,&l,&r);

         if(c=='M')

         {

             for(int j=l; j<=r; j++)

                 p[][j]++;

         }

         else

         {

             for(int j=l; j<=r; j++)

                 p[][j]++;

         }

     }

     int ans=;

     for(int i=; i<=; i++)

         ans=max(ans,*min(p[][i],p[][i]));

     cout<<ans<<endl;

     return ;

 }