A threat vulnerability matrix assigns risk scores based on Likelihood (1-5) multiplied by Impact (1-5). A vulnerability is rated 'Critical' if the score is 16 or higher. If a system has 4 vulnerabilities with the following (Likelihood, Impact) ratings: V1(4, 3), V2(3, 5), V3(5, 4), V4(2, 5), how many vulnerabilities are classified as Critical?