loop dekakin nuth karanna puluwn kolaweri dala tiyenwa wage lassanta enne ne habai
isselama array ekakata marks tika gannawa uba karala tiyenwa wage. itapasse for loop ekakin sum eka gannawa.
array length eken sum eka bedanawa. meke result eka tamai average eka.
(divide by zero walata check...