exception and profil link

@@ -26,7 +26,14 @@ class InputProfilFirstTwoActivity : AppCompatActivity() {
 
 
             var birthdateinput=findViewById<EditText>(R.id.editText).text.toString()
-                var birthdateint=birthdateinput.toInt()
+            var birthdateint = 0
+            if (birthdateinput == "") {
+                birthdateint = 0
+            }
+            else {
+                birthdateint = birthdateinput.toInt()
+            }
+
             if ((2019-birthdateint)<19){
                 editor.putInt("c1_2",1)
                 editor.commit()

@@ -101,7 +101,7 @@ class InputProfilFourthOneActivity : AppCompatActivity() {
                 editor.putInt("c7_31",1)
                 editor.commit()
             }
-            var intent = Intent(this, InputProfilFirstTwoActivity::class.java)
+            var intent = Intent(this, InputProfilFourthTwoActivity::class.java)
             startActivity(intent)
         }
     }

@@ -81,7 +81,7 @@ class SignUpActivity : AppCompatActivity() {
                     cnt ++
 
                     if(user!=null){
-                        var intent = Intent(this, MainActivity::class.java)
+                        var intent = Intent(this, InputProfilFirstOneActivity::class.java)
                         startActivity(intent)
                     }
                 } else {