ll@t;
rep(t){
	ll@n,@k;
	ll@p11,@p12,@p13;
	ll@p21,@p22,@p23;
	ll@p31,@p32,@p33;
	ll@a[n];
	string@s;
	char d[606];
	rep(j,606){
		d[j]=j%6?'D':j>=k*6?'K':'P';
	}
	rrep(i,n){
		char e[606];
		rep(j,606){
			e[j]=d[j];
		}
		int b=a[i]+1;
		rep(j,1,606){
			char ej=e[j*b%606];
			if(ej==s[i]||ej=='D'&&d[j]!=s[i]){
				d[j]=ej;
			}
		}
	}
	ll h=abs(p11*(p22*p33-p23*p32)+p12*(p23*p31-p21*p33)+p13*(p21*p32-p22*p31));
	wt(h==0?'D':d[h%606]);
}