#nterm=int(input("Input the number of terms:"))
#n1=0
#n2=1
#count=0
#while(count<nterm):
#    print(n1,",")
#    nth=n1+n2
##    n1=n2
 #   n2=nth
 #   count=count+1
i=1 
a=int(input("Enter a number : "))
factorial =1
while i<=a:
    factorial=factorial*i
    i=i+1
print(factorial)    
