def finalState(operations):
    if not operations:
        return 0
    
    max_index = 0
    for left, right in operations:
        max_index = max(max_index, right)
    
    states = [False] * (max_index + 1)
    toggles = [0] * (max_index + 2)  
    
    for left, right in operations:
        toggles[left] += 1
        if right + 1 <= max_index:
            toggles[right + 1] -= 1
    
    toggle_count = 0
    for i in range(max_index + 1):
        toggle_count += toggles[i]
        if toggle_count % 2 == 1:
            states[i] = not states[i]
    
    sum_indices = 0
    for i in range(max_index + 1):
        if states[i]:
            sum_indices += i
    
    return sum_indices