codekata, problem

You are given three numbers A, B & C. Print the largest amongst these three numbers.

Input Description:
Three numbers are provided to you.

Output Description:
Find and print the largest among the three

Sample Input :
1
2
3

Sample Output :
3

i have given below code, testcase 1 is pass and testcase 2 is fail what does it mean ?please help and correct the code

a=1

b=2

c=3

if (a>b) and (a>c):

print(a)

elif (b>a) and (b>c):

print(b)

else:

print(c)