#include<iostream>
#include<cstring>
using namespace std;
#define MAX 200200
char ch[MAX];
int ans,tot;
int main()
{
	cin>>(ch+1);
	for(int i=1,l=strlen(ch+1);i<=l;++i)
		if(ch[i]=='S')++tot;
		else tot?--tot:++ans;
	printf("%d\n",ans+tot);
	return 0;
}
