src.c:1:6: error: expected expression before 'int'
n1 = int(input(''))
^
src.c:1:16: error: empty character constant
n1 = int(input(''))
^
src.c:2:16: error: empty character constant
n2 = int(input(''))
^
src.c:3:16: error: empty character constant
n3 = int(input(''))
^