The mn blood group system is co dominant | Homework Helpers

The MN blood group system is codominant and has three genotypes: NN, MM, and MN. In a population of 4250 people, 16% had blood type N.  A disease was introduced to the population after an escaped research monkey bit one of the village inhabitants.  This disease killed all of the individuals with blood type M, and while those that had blood type N all survived, the treatment for the disease killed them all.  After several weeks, life returned to normal in the village.  What genotype and phenotype frequencies would be expected as the result of this disease (selection)?  What genotype and phenotype frequencies would we expect to find for the MN blood group system in subsequent generations?  Assume that Hardy-Weinberg equilibrium was initially in effect  Just practice but I can’t even figure this one out.