Resolve an use case with dynamic programming

An organizer of a running race wishes to purchase (atlease) n identical T-shirts(same size) for participants. At a wholesale, T-shirts are packaged at different prices depending on the number of T-shirts in the package. The organizer can buy any number of packages of each size (size here is not the T-shirt size, it is the number of T-shirts in a package), as long as the total number is atlease n. The organizer wishes to find the minimum total price of such a set of packages. The input is given as n and an array packages [1.m], where each package[i] has a positive integer field package[i].size and a positive real field Package[i].price, giving the number of T-shirts in the package and the price of the package, respectively.