With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Sierra Leone became an independent nation in 1961.
text_B: The Schutte-Lanz D.IV was a German fighter prototype during World War I .. German. Germany. World War I. World War I. It was developed in parallel with the Schutte-Lanz D.III , however the two fighters had nothing in common .. Schutte-Lanz D.III. Schutte-Lanz D.III. The D.IV was made of wood and was a single-bay staggered biplane with N-type interplane struts and ailerons on both upper and lower mainplanes .. single-bay. single-bay. It first flew in late 1917 and was found to be inferior to the Schutte-Lanz D.III , and as a result production was not started .. Schutte-Lanz D.III. Schutte-Lanz D.III. A second prototype , designated D.IVa , was built with minor improvements including a frontal radiator and revised undercarriage .
not_related.