deleted / lost all applications

Hello, while working in Pages on Macbook AIR 2013 lost all of the launchpad program and folder Programs. They can not be found through search and download in safety standard mode and reboot - did not help. Otsutvie absolutely all applications, including terminal, Disk Utility and others, there is only an icon Pages, but it does not work. Please tell me how to restore the program? Thanks in advance. Translated by Google Translate. Mac OS X 10.10.2