import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.math, std.typecons, std.container, core.bitop;
import std.numeric;

void main() {
    string x;
    scan(x);

    int st, ans;

    foreach (ch ; x) {
        if (ch == 'S') {
            st++;
        }
        else {
            if (st > 0) {
                st--;
            }
            else {
                ans++;
            }
        }
    }

    ans += st;
    writeln(ans);
}


void scan(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}



void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}