Timeline of Albanian history to 1993 cooperation signed with Yugoslavia; Yugoslav advisers and grain begin pouring into Albania. October<br> 26 October: Two British ships destroyed by mines off Albania's coast in the Straits of Corfu, see Corfu Channel Incident, . November<br> Albania breaks diplomatic relations with the United States after the latter withdraws its informal mission. 1947 April May<br> A United Nations commission concludes that Albania, together with Bulgaria and Yugoslavia, supported communist guerrillas in the Greek Civil War; Yugoslav leaders launch verbal offensive against anti-Yugoslav Albanian communists, including Hoxha; pro-Yugoslav faction begins to wield power. July<br> Albania refuses participation in the Marshall Plan of the
Closest string of the closest string problem, which is NP-complete, instead takes "k" as another input and questions whether there is a string within Hamming distance "k" of all the input strings. The closest string problem can be seen as an instance of the 1-center problem in which the distances between elements are measured using Hamming distance. In bioinformatics, the closest string problem is an intensively studied facet of the problem of finding signals in DNA. Instances of closest string may contain information that is not essential to the problem. In some sense, the usual input of closest string contains information, that