import std.stdio, std.conv, std.functional, std.string; import std.algorithm, std.array, std.container, std.range, std.typecons; import std.bigint, std.numeric, std.math, std.random; import core.bitop; string FMT_F = "%.10f"; static File _f; void file_io(string fn) { _f = File(fn, "r"); } static string[] s_rd; T _RD(T = long)() { while(!s_rd.length) s_rd = readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; } T _RD(T = long)(File f) { while(!s_rd.length) s_rd = f.readln.chomp.split; string res = s_rd[0]; s_rd.popFront; return res.to!T; } T[] _RDA(T = long)(T fix = 0) { auto r = readln.chomp.split.to!(T[]); r[] += fix; return r; } T[] _RDA(T = long)(File f, T fix = 0) { auto r = f.readln.chomp.split.to!(T[]); r[] += fix; return r; } T RD(T = long)() { if (_f.isOpen) return _RD!T(_f); else return _RD!T; } T[] RDA(T = long)(T fix = 0) { if (_f.isOpen) return _RDA!T(_f, fix); else return _RDA!T(fix); } size_t[] MAKE_IDX(alias less = "a < b", Range)(Range range) { auto idx = new size_t[](range.length); makeIndex!(less)(range, idx); return idx;} size_t MIN_POS(alias less = "a < b", Range)(Range range) { auto r = minPos!(less)(range); return range.length - r.length; } void chmin(T)(ref T x, T y) { x = min(x, y); } void chmax(T)(ref T x, T y) { x = max(x, y); } bool inside(T)(T x, T b, T e) { return x >= b && x < e; } T lcm(T)(T x, T y) { return x * (y / gcd(x, y)); } double euDist(T)(T[] a, T[] b) { auto c = a.dup; c[] -= b[]; c[] *= c[]; return sqrt(cast(double)c.sum); } double[] rotate(double[] vec, double rad) { return [cos(rad)*vec[0] - sin(rad)*vec[1], sin(rad)*vec[0] + cos(rad)*vec[1]]; } double norm(double[] vec) { return sqrt(reduce!((a,b)=>a+b*b)(0.0, vec)); } double dotProd(double[] a, double[] b) { auto r = a.dup; r[] *= b[]; return r.sum; } //long mod = 10^^9 + 7; long mod = 998_244_353; //long mod = 1_000_003; void moda(ref long x, long y) { x = (x + y) % mod; } void mods(ref long x, long y) { x = ((x + mod) - (y % mod)) % mod; } void modm(ref long x, long y) { x = (x * y) % mod; } void modpow(ref long x, long y) { if (!y) { x = 1; return; } auto t = x; x.modpow(y>>1); x.modm(x); if (y&1) x.modm(t); } void modd(ref long x, long y) { y.modpow(mod - 2); x.modm(y); } void main() { auto T = RD; auto ans = new char[][](T); foreach (ti; 0..T) { auto N = RD; auto S = RD!string; auto link = new long[][](N+2); foreach (long i; 0..N+2) { link[i] = [i-1, i+1]; } long i = 1; while (i <= N) { debug writeln("i:", i); debug writeln(link); debug { string tmp; long pos = link[0][1]; while (pos <= N) { tmp ~= S[pos-1]; pos = link[pos][1]; } writeln(tmp); } auto j = link[i][1]; if (j == N+1) break; auto k = link[j][1]; if (k == N+1) break; if (S[i-1] == 'A' && S[j-1] == 'B' && S[k-1] == 'B') { auto jj = link[i][0]; link[jj][1] = k; link[k][0] = jj; auto ii = link[jj][0]; if (ii <= 0) break; i = ii; } else i = link[i][1]; } long pos = link[0][1]; while (pos <= N) { ans[ti] ~= S[pos-1]; pos = link[pos][1]; } } foreach (e; ans) writeln(e); stdout.flush; debug readln; }