diff --git a/drama/src/rev-mc.c b/drama/src/rev-mc.c
index a64150e..8a4ae82 100644
--- a/drama/src/rev-mc.c
+++ b/drama/src/rev-mc.c
@@ -327,14 +327,14 @@ find_row_mask(std::vector<set_t> &sets,
     std::vector<std::thread> workers;
     auto thread_num = cpu == 0 ? std::thread::hardware_concurrency() : cpu;
     if (thread_num > 2) { thread_num -= 2; }
-    fprintf(stderr, "thread_num: %ld", thread_num);
+    fprintf(stderr, "thread_num: %ld\n", thread_num);
 
-    uint64_t step = 0;
-    for (uint64_t i = row_mask; i < last_mask; ++step) { i = next_bit_permutation(i); }
-    fprintf(stderr, "total_step: %ld", step);
-    step /= thread_num;
-    fprintf(stderr, "worker_step: %ld", step);
-    if (!step) { ++step; }
+    uint64_t step = 1 << 20;
+    // for (uint64_t i = row_mask; i < last_mask; ++step) { i = next_bit_permutation(i); }
+    // fprintf(stderr, "total_step: %ld\n", step);
+    // step /= thread_num;
+    // if (!step) { ++step; }
+    fprintf(stderr, "worker_step: %ld\n", step);
 
     for (int i = 0; i < thread_num; ++i) {
         workers.emplace_back([&] {