CREATE TABLE table_28991 ("Proto-Slavic" TEXT, "Russian" TEXT, "Ukrainian" TEXT, "Belarusian" TEXT, "Polish" TEXT, "Czech" TEXT, "Slovak" TEXT, "Slovene" TEXT, "Serbo-Croatian" TEXT, "Bulgarian" TEXT, "Macedonian" TEXT)

When ( ) / gn(ij)ezdo is the serbo-croatian how many proto-slavics are there?
SELECT COUNT("Proto-Slavic") FROM table_28991 WHERE "Serbo-Croatian" = 'гн(иј)ездо / gn(ij)ezdo'
SELECT COUNT("Proto-Slavic") FROM "table_28991" WHERE "Serbo-Croatian" = 'гн(иј)ездо / gn(ij)ezdo'