How do you do addition in C programming?

c programming question and need guidance to help me learn.

Start
Declare variables num1, num2, and res.
Read values for num1 and num2.
Add the values of num1 and num2 and assigned the result to a res variable.
Print res.
Stop.
Requirements:
1CPROGRAMMING:ANOTHERWEIRDSUM!Wearegoingnowtocomputethissum:x−x33!+x55!−x77!+···+xNN!Itlooksliketheexponentialthatwejustdid,exceptwithonlytheoddpowersandalsowithsomeminussignssprinkledin./*thisisaprogramtodoasecondweirdsum*/#include#includeintmain(void){doubleprod=1,sum=0,x;intj,N;printf(“EnterNandx”);printf(“\n”);scanf(“%i%lf”,&N,&x);for(j=1;j