How do I resolve my LNK2019 error in my program?

// Program to print BFS traversal from a given

// source vertex. BFS(int s) traverses vertices

// reachable from s.

#include<iostream>
#include <list>

using namespace std;

// This class represents a directed graph using

// adjacency list representation

class Graph
{
    int V;    // No. of vertices

    // Pointer to an array containing adjacency

    // lists

    list<int> *adj;  

public:

    Graph(int V); // Constructor

    // function to add an edge to graph

    void addEdge(int v, int w);

    // prints BFS traversal from a given source s

    void BFS(int s);
};

Graph::Graph(int V)
{
    this->V = V;

    adj = new list<int>[V];
}

void Graph::addEdge(int v, int w)
{
    adj[v].push_back(w); // Add w to v’s list.
}

void Graph::BFS(int s)
{
    // Mark all the vertices as not visited

    bool *visited = new bool[V];

    for(int i = 0; i < V; i++)

        visited[i] = false;

    // Create a queue for BFS

    list<int> queue;

    // Mark the current node as visited and enqueue it

    visited[s] = true;

    queue.push_back(s);

    // 'i' will be used to get all adjacent

    // vertices of a vertex

    list<int>::iterator i;

    while(!queue.empty())
    {

        // Dequeue a vertex from queue and print it

        s = queue.front();

        cout << s << " ";

        queue.pop_front();

        // Get all adjacent vertices of the dequeued

        // vertex s. If a adjacent has not been visited,

        // then mark it visited and enqueue it

        for (i = adj[s].begin(); i != adj[s].end(); ++i)
        {
            if (!visited[*i])
            {
                visited[*i] = true;

                queue.push_back(*i);
            }
        }
    }
}

// Driver program to test methods of graph class

int main()
{
    // Create a graph given in the above diagram

    Graph g(4);

    g.addEdge(0, 1);

    g.addEdge(0, 2);

    g.addEdge(1, 2);

    g.addEdge(2, 0);

    g.addEdge(2, 3);

    g.addEdge(3, 3);

    cout << "Following is Breadth First Traversal "

         << "(starting from vertex 2) \n";

    g.BFS(2);

    return 0;
}

Severity	Code	Description	Project	File	Line	Suppression State
Error	LNK2019	unresolved external symbol _WinMain@16 referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)	MIbasco_Project7	C:\Users\Ibascos\source\repos\MIbasco_Project7\MSVCRTD.lib(exe_winmain.obj)	1