Undefined reference in C ++

I'm studying c ++ and found a problem when working with object orientation, I followed some tutorials but it did not work.

Account.h

#ifndef CONTA_H
#define CONTA_H

#include <string>

using namespace std;

class Conta{

    private:
        string nome;
        int idade;

    public:
        string getNome();
        int getIdade();
};

#endif // CONTA_H

Account.cpp

#include "Conta.h"
#include <string>

using namespace std;

string Conta::getNome(){
    return nome;
}

int Conta::getIdade(){
    return idade;
}

main.cpp

#include <iostream>
#include "Conta.h"

using namespace std;

int main()
{
    Conta p;

    cout << p.getNome() << endl;
    return 0;
}

When I compile the code it brings me this error.

undefined reference to 'Conta::getNome()'

Obs: My Ide is CodeBlocks.