Network Structures

4. There are 50 farms along a 50-mile-long stretch of a river. Each farmer lives on a tract of land that occupies a 1-mile stretch of the river bank, so their tracts exactly divide up the 50 miles of riverbank they collectively cover. The farmers all know each other. Each farmer is friends with all the other farmers that live at most 20 miles from him or her, and are enemies with all the farmers that live more than 20 miles from him or her. Consider the signed complete graph corresponding to this social network. Is the network structurally balanced or not?