Refer to the following number and symbol series and answer the question…

Refer to the following number and symbol series and answer the question given below. Counting is to be done from left to right only. (All numbers are single-digit numbers only.)
निम्नलिखित संख्या एवं प्रतीक श्रृंखला का अध्ययन कीजिए और दिए गए प्रश्न का उत्तर दीजिए। गणना केवल बाएँ से दाएँ की जाएगी। (सभी संख्याएँ एक-अंकीय हैं।)

(Left) 7 $ 4 1 7 1 9 6 2 + 5 = 6 3 % 7 5 # 8 @ 4 5 & 7 8 (Right)

How many such symbols are there each of which is immediately preceded by an odd number and immediately followed by an even number?
ऐसे कितने प्रतीक हैं जिनके ठीक पहले विषम संख्या तथा ठीक बाद सम संख्या है?