Problems(1)
Let r be a positive integer. Find the smallest positive integer m satisfying the condition: For all sets A1,A2,…,Ar with Ai∩Aj=∅, for all i=j, and ⋃k=1rAk={1,2,…,m}, there exists a,b∈Ak for some k such that 1≤ab≤1+20221. combinatorics