Compiling error mecanum drive

I am fairly new to text coding and I’m working on a mecanum drive using arcade controls for the right side and I attempted to compile the code and i got this error ’ unix build for platform vexv5

CXX src/main.cpp

LINK build/Mecanum.elf

arm-none-eabi-ld: /home/ubuntu/cloudcompiler/Tools/sdk/vexv5/20220726_10_00_00/libv5rt.a(v5_startup.c.obj): in function `vexMain’:

(.text.vexMain+0xa0): undefined reference to `main’

make: *** [vex/mkrules.mk:18: build/Mecanum.elf] Error 1

make process closed with exit code : 2’
I’m not sure what to do

Could you send your full code so that we can help you better?

'#pragma region VEXcode Generated Robot Configuration
// Make sure all required headers are included.
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include <string.h>


#include "vex.h"

using namespace vex;

// Brain should be defined by default
brain Brain;


// START V5 MACROS
#define waitUntil(condition)                                                   \
  do {                                                                         \
    wait(5, msec);                                                             \
  } while (!(condition))

#define repeat(iterations)                                                     \
  for (int iterator = 0; iterator < iterations; iterator++)
// END V5 MACROS


// Robot configuration code.
controller Controller1 = controller(primary);
motor Claw = motor(PORT5, ratio18_1, false);

motor Arm = motor(PORT6, ratio18_1, false);

motor Back_left = motor(PORT7, ratio18_1, false);

motor Back_Right = motor(PORT8, ratio18_1, true);

motor Front_left = motor(PORT11, ratio18_1, false);

motor Front_right = motor(PORT20, ratio18_1, true);




// define variable for remote controller enable/disable
bool RemoteControlCodeEnabled = true;
#pragma endregion VEXcode Generated Robot Configuration
// Include the V5 Library
#include "vex.h"
  
// Allows for easier use of the VEX Library
using namespace vex;

float myVariable;

int whenStarted1() {
  //deadzone
  while (true) {
    int threshold = 10;
    int a = Controller1.Axis1.value();
    int b = Controller1.Axis2.value();
    int c = Controller1.Axis3.value();
    int d = Controller1.Axis4.value();
if(abs(a)<threshold){
    a=0;
}
if(abs(b)<threshold){
    b=0;
}
if(abs(c)<threshold){
    c=0;
}
if(abs(d)<threshold){
    d=0;
}
    //Foward
    Back_left.setVelocity((Controller1.Axis2.position() + Controller1.Axis1.position()), percent);
    Back_Right.setVelocity((Controller1.Axis2.position() + Controller1.Axis1.position()), percent);
    Front_left.setVelocity((Controller1.Axis2.position() + Controller1.Axis1.position()), percent);
    Front_right.setVelocity((Controller1.Axis2.position() + Controller1.Axis1.position()), percent);
    Back_left.spin(forward);
    Back_Right.spin(forward);
    Front_left.spin(forward);
    Front_right.spin(forward);
    //Backwards
    Back_left.setVelocity((Controller1.Axis2.position() - Controller1.Axis1.position()), percent);
    Back_Right.setVelocity((Controller1.Axis2.position() - Controller1.Axis1.position()), percent);
    Front_left.setVelocity((Controller1.Axis2.position() - Controller1.Axis1.position()), percent);
    Front_right.setVelocity((Controller1.Axis2.position() - Controller1.Axis1.position()), percent);
    Back_left.spin(reverse);
    Back_Right.spin(reverse);
    Front_left.spin(reverse);
    Front_right.spin(reverse);
    //Left
    Back_left.setVelocity((Controller1.Axis1.position() - Controller1.Axis2.position() ), percent);
    Back_Right.setVelocity((Controller1.Axis1.position() - Controller1.Axis2.position() ), percent);
    Front_left.setVelocity((Controller1.Axis1.position() - Controller1.Axis2.position() ), percent);
    Front_right.setVelocity((Controller1.Axis1.position() - Controller1.Axis2.position() ), percent);
    Back_left.spin(reverse);
    Back_Right.spin(forward);
    Front_left.spin(forward);
    Front_right.spin(reverse);
  wait(5, msec);
    }
  return 0;
  }
'

Also any tips on how to write this better would also be greatly appreciated