diff --git a/kwmr_solver.py b/kwmr_solver.py
index f1b00dc1201510f9505c4c94fdb7aac6a139dd58..72cef3c53ac3d0232bdc8e2355af209d48956d8a 100644
--- a/kwmr_solver.py
+++ b/kwmr_solver.py
@@ -1,5 +1,6 @@
 import argparse
 import os
+import random
 import subprocess
 
 proc = None
@@ -22,10 +23,8 @@ def solve(params):
 
     # 必要な変数があるか確認
     assert('problem' in params)
-    assert('timeout' in params)
 
     problem = params['problem']
-    timeout = params['timeout']
 
     basedir = os.path.abspath(os.path.dirname(__file__))
 
@@ -33,7 +32,9 @@ def solve(params):
     if os.path.exists(solution_filepath):
         os.remove(solution_filepath)
 
-    cmds = f'{basedir}/solver_soft/sim -o {solution_filepath}'.split()
+    seed = random.randint(0, 2147483647) # seed: uint32_t <= 2147483647
+
+    cmds = f'{basedir}/solver_soft/sim -o {solution_filepath} -s {seed}'.split()
 
     proc = subprocess.Popen(
         cmds,
@@ -43,20 +44,15 @@ def solve(params):
     )
 
     try:
-        # outs, errs = proc.communicate()
         proc.communicate(problem.encode())
         status = 'done'
     except Exception as ex:
         status = 'failed'
     finally:
         returncode = proc.returncode
-        # outs = outs.decode()
-        # errs = errs.decode()
-        # print(outs)
-        # print(errs)
 
     solution = ''
-    if returncode == 0:    # 10 when SAT
+    if returncode == 0:
         status = 'done'
         if os.path.exists(solution_filepath):
             with open(solution_filepath, 'r') as fp: