What's wrong

[kinngu]

What's wrong with this code?

n = int(input())
m = [int(i) for i in input().split()]
l = []
for i in range(n):
    if m[i] != -1:
        l.append(m[i])
l.sort()
for i in range(n):
    if(m[i] != -1) and m[i] in l: 
        m[i] = l[0]
        del l[0]
for i in range(n):
    print(m[i], end = ' ')

It's supposed to rearrange the inputs the increasing manner, except for -1's.

My input:
4
949 -1 3957 949
My output:
949 -1 949 949
How did that happen?

[Larz60+]

First of all, learn to use meaningful names, single letter are meaningless to another programmer.
Next, Add text to input statements indicating what is expected.
example:

n = int(input('Enter number of items: ')
m = [int(i) for i in input('Enter the items : ').split()]

First statement:

n = int(input())

is not needed, and no need to terminate with -1 use instead:

for i in range(len(m)):

this code:

for i in range(n):
    if m[i] != -1:
        l.append(m[i])

is totally unnecessary, you already have the values in m
finally, you show your input, and actual output, but not your desired output which is important