implemented contrast slider

mainwindow.cpp

@@ -58,13 +58,14 @@ std::string MainWindow::makeRequestToOfd(std::string captcha) {
         ui->total_edit->text().toDouble() * 100,
         captcha);
 
-    return checkContent
+    return checkContent;
 }
 
 void MainWindow::receiveSolvedCaptcha(std::string captcha) {
 
     std::string check_content = makeRequestToOfd(captcha);
 
+    std::cout << check_content << std::endl;
 
 }