Out of range. How to add the remainder of list to accumulator?

I get [-7,-4,-2], but I want to add the remaining numbers to my accumulator but I keep going out of range in my second if statement. How would I continue to add the remaining list? input: interleaved( [-7, -2, -1], [-4, 0, 4, 8])

def interleaved(seq1,seq2):
i = 0
j = 0
res = []

    

while i <len(seq1) and j <len(seq2):
    if seq1[i] < seq2[j]:
        res.append(seq1[i])
        i+=1
    if  seq2[j] <= seq1[i]:
        res.append(seq2[j])
        j+=1
return res

Added an if statement to check whether we "finished" exploring seq1 or not (same if "check" can be applied on seq2 in case it had more negative values than seq1)

def interleaved(seq1, seq2):
    i = 0
    j = 0
    res = []

    while i < len(seq1) and j < len(seq2):
        if seq1[i] < seq2[j]:
            res.append(seq1[i])
            i += 1
            if i == len(seq1):  # If we explored all of seq1 (reached the end)
                for num in seq2[j:]:  # Explore the rest of seq2
                    res.append(num)  # Append the rest
                break  # Break the while loop and go to "return"
        if seq2[j] <= seq1[i]:
            res.append(seq2[j])
            j += 1

    return res

print(interleaved())