Insert:
        addi $sp, $sp,-12
        sw $ra,$sp
        sw $a0,4($sp) #key
        sw $a1,8($sp) #leaf

        lw $t0,($a1)    #*leaf
        bne $t0,$zero,Else_if_Left
        lw $t3,4($sp)    #Key
        li $a0,12
        li $v0,9
        syscall
        lw $t0,$v0       #leaf is t0
        sw $t3,0($t0)    #(*leaf)->key_value=key;
        sw $zero,4($t0)  #(*leaf)->left=0
        sw $Zero,8($t0)  #(*leaf)->right=0
        j epilogo

        Else_if_Left:
                    lw $t1,$t0 #(*leaf)->key
                    slt $t2,$t3,$t1 #else if(key< (*leaf)->key_value)
                    beq $t2,$zero,Else_if_Right
                    #assignation of parameters (key, leaf)
                    add $a0,$zero,$t3
                    lw $t2,4($t0)
                    add $a1,$zero,$t2
                    jal Insert
        Else_if_Right:
                    slt $t2,$t1,$t3 #else if(key> (*leaf)->key_value)
                    beq $t2,$zero,Epilogo
                    #assignation of parameters (key, leaf)
                    add $a0,$zero,$t3
                    lw $t2,8($t0)
                    add $a1,$zero,$t2
                    jal Insert
        Epilogo:
                lw $ra,$sp
                addi $sp,$sp,12
                jr $ra