It's בס"ד. Meaning the three letters ב ס ד, with the gershayim mark between the last two indicating it is an abbreviation. The letters stand for בסיעתא דשמיא, which means "with the help of heaven". Technically, it is Aramaic, but the abbreviation is used in Hebrew.
Jews often write this on the top of anything they write to show that their work is not entirely their own doing because is done with the help of heaven.
PS: This looks like a child's handwriting. Maybe someone 6-8 years old.
שתה וגם גמליך אשקה