In “counting subsets”, we saw that the total number of subsets of a set s containing n elements is equal to 2n. however, if we intend to count the total number of subsets of s having a fixed size k, then we use the combination statistic c(n, k), also written (nk). given: positive integers n and m with 0≤m≤n≤2000. return: the sum of combinations c(n, k) for all k satisfying m≤k≤n, modulo 1,000,000. in shorthand, ∑nk=m(nk).