--- /dev/null
+#include<cstdio>
+#include<cstdlib>
+#include<ctime>
+#include<unistd.h>
+
+int main(void){
+ srand(time(NULL));
+ for(int i=0;i<100;i++){
+ int nr = rand() % 100;
+ printf("%d\n", nr);
+ fflush(stdout);
+ int ret;
+ scanf("%d", &ret);
+ if(ret != nr + 1){
+ fprintf(stderr, "bad ret: %d instead of %d", ret, nr + 1);
+ return 1;
+ }
+ }
+
+ if(write(4, "20", 2) == -1)
+ perror("write");
+ return 0;
+}