With no explanation, label text_A→text_B with either "entailment", "neutral" or "contradiction".
text_A: Bulgaria was neutral during 1939-1941, but on March 1, 1941, Bulgaria signed the Tripartite Pact and officially joined the Axis bloc.
text_B: on March 1, 1941, Bulgaria signed the Tripartite Pact and officially joined the Axis bloc.
entailment.