if statement in R can only have one line?

Question

I was trying a tiny code with if statement, although it is very simple,but there is something I really confused here is the code

n<-857
while(n!=1){
if(n         


        

Answer 1

Ever heard of curly barces?

n<-857
while(n!=1){
    if(n<=0) {
        print("please input a positive integer")
    } else if(n%%2==0) {
        n<-n/2
        print(n)
    } else {
        n<-3*n+1
        print(n)
    }
}