https://codeforces.com/contest/1187/problem/F \documentclass[margin=2mm]{standalone} \usepackage{amsmath,amssymb,bussproofs} \begin{document} %\begin{prooftree} \AxiomC{\(N^2\)} \UnaryInfC{\(E[N^2]\)} \AxiomC{\(\displaystyle \sum_{i} \Pr[x…