CREATE TABLE table_26757_4 (proto_slavic VARCHAR(255), serbo_croatian VARCHAR(255))
When  гн(иј)ездо / gn(ij)ezdo is the serbo-croatian how many proto-slavics are there?
    
SQL: SELECT COUNT(proto_slavic) FROM table_26757_4 WHERE serbo_croatian = "гн(иј)ездо / gn(ij)ezdo"