Complex sentence: In the first round, a victorious candidate requires an absolute majority in both the 200-seat Chamber of Deputies and the 81-seat Senate, i.e.101 deputies and 41 senators.
Split into simpler sentences: In the first round, a victorious candidate requires an absolute majority in both the Chamber of Deputies and the Senate. Given a 200-seat Chamber and an 81-seat Senate, a successful first round candidate would have required 101 deputies and 41 senators.