diff --git a/3.3(2).txt b/3.3(2).txt
new file mode 100644
index 0000000..989301a
--- /dev/null
+++ b/3.3(2).txt
@@ -0,0 +1,49 @@
+
+#include <stdio.h>   
+#include <stdlib.h>   
+#include <pthread.h>   
+#include <unistd.h>   
+#include <sys/types.h>   
+#include <semaphore.h>   
+sem_t A, B, C;
+void* p1(void *arg){
+    
+	for(int i=0;i<10;i++){
+    sem_wait(&C);
+	printf("A\n");
+    sem_post(&A);
+    }
+     usleep(1000*1000);
+} 
+void* p2(void *arg){
+    
+	for(int i=0;i<10;i++){
+    sem_wait(&A);
+	printf("B\n");
+    sem_post(&B);
+	}
+     usleep(1000*1000);
+} 
+void* p3(void *arg){
+    
+	for(int i=0;i<10;i++){
+        sem_wait(&B);
+	printf("C\n");
+     sem_post(&C);
+	}
+   
+     usleep(1000*1000);
+} 
+
+int main()  
+{   sem_init( &A, 0,0);
+    sem_init( &B, 0,0);
+    sem_init( &C, 0,1);
+	pthread_t tid[3];  
+	pthread_create(&tid[0], NULL, p1, NULL);  
+	pthread_create(&tid[1], NULL, p2, NULL);  
+	pthread_create(&tid[2], NULL, p3, NULL);  
+	for(int i = 0; i < 3; i++)  
+		pthread_join(tid[i], NULL);      
+	printf("main is over\n");
+}