findfact=function(n){
    factorial=1
    
    if(n<0)
    print("Factorial of negative number is not possible")
    else if(n == 0)
    print("Factorial of 0 is 1")
    else{
    for(i in 1:n)
    factorial=factorial*i
    print(paste("Factorial of ",n," is ",factorial))
    }
}
n=as.integer(readline("Enter one number to find factorial"))
findfact(n)