diff --git a/src/inport/ConversionUtils/Solver.java b/src/inport/ConversionUtils/Solver.java
index 248a2892397c49053cd91a7e475bb1b93adfc645..e44a29fb7d45cc3d7b3e13eda1dbfd9b8637ff1f 100644
--- a/src/inport/ConversionUtils/Solver.java
+++ b/src/inport/ConversionUtils/Solver.java
@@ -56,12 +56,31 @@ public class Solver {
             directory.mkdir();
         }
 
-        tempDir = tempDir + "/";
+        File candidate = new File(tempDir + "/1/");
+
+        final int limitOfDirectories = 1000000;
+
+        int i = 1;
+        while (i < limitOfDirectories) {
+            candidate = new File(tempDir + "/" + i + "/");
+            if (candidate.mkdir()) {
+                break;
+            }
+            i++;
+        }
+
+        if (i == limitOfDirectories) {
+            return "Impossible to create files from " + tempDir + "/1/ to " + tempDir + "/" + (limitOfDirectories - 1) + "/ .";
+        }
+
+        tempDir = tempDir + "/" + i + "/";
         String minizincData        = tempDir + "minizinc_data.dzn";
         String solverResults       = tempDir + "solver_results.txt";
         String constraints         = tempDir + "constraints.mzn";
         String flatZincConstraints = tempDir + "model.fzn";
 
+        new File(solverResults).delete();
+
         try {
             try (FileWriter res = new FileWriter(constraints)) {
                 BufferedReader reader = new BufferedReader(new InputStreamReader(Main.class.getResourceAsStream("/constraints/" + constraintName)));
@@ -133,6 +152,9 @@ public class Solver {
                 }
             });
 
+            BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
+//            BufferedReader br2 = new BufferedReader(new InputStreamReader(process.getErrorStream()));
+
             killer.start();
             int exitCode = process.waitFor();
 
@@ -156,20 +178,16 @@ public class Solver {
 
             if (isResultsInOutput) {
                 try (FileWriter res = new FileWriter(solverResults)) {
-                    BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
                     res.write(br.lines().collect(Collectors.joining("\n")));
                 }
                 interpreter.accept(task, solverResults);
             } else {
 
-                BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
                 String output = br.lines().collect(Collectors.joining("\n"));
-
-//            BufferedReader br2 = new BufferedReader(new InputStreamReader(process.getErrorStream()));
-//            String errors = br.lines().collect(Collectors.joining("\n"));
-
-//            System.out.println("output : " + output);
-//            System.out.println("errors : " + errors);
+//                String errors = br.lines().collect(Collectors.joining("\n"));
+//
+//                System.out.println("output : " + output);
+//                System.out.println("errors : " + errors);
 
                 if (output.trim().equals("=====UNSATISFIABLE=====")) {
                     task.setSolution(new ArrayList<>());
@@ -181,7 +199,7 @@ public class Solver {
         } catch (UncheckedIOException | IOException | InterruptedException | ParserException ex) {
             return ex.getMessage();
         } finally {
-//            removeDirectory(directory);
+            removeDirectory(candidate);
         }
         return "";
     }