diff --git a/Makefile b/Makefile
index 03a172f..dc5c6fd 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ DIRS = $(sort $(wildcard src/*))
 
 all:
 	for i in $(DIRS); do echo $$i; make -s -C $$i; done
-#t: all
+t: all
 #	for i in $(DIRS); do echo $$i; $$i/t; done
 b: all
 	for i in $(DIRS); do echo $$i; $$i/b; done
diff --git a/common/b.c b/common/b.c
index 6fa1963..91f137e 100644
--- a/common/b.c
+++ b/common/b.c
@@ -26,6 +26,7 @@ static unsigned long long dt;
 
 #define SEC  1000000000ULL
 #define MAXN  500000000
+#define MINT (SEC/5)
 
 static unsigned long long tic() {
 	struct timespec ts;
@@ -59,9 +60,9 @@ static int nextN() {
 	unsigned long long i;
 
 	if (n)
-		n = SEC/2/n;
+		n = MINT/n;
 	else
-		n = SEC/2;
+		n = MINT;
 	n += n/2;
 	if (n > N*100ULL)
 		n = N*100ULL;