#include <stdio.h>
int trb(int n){
if(n==0){
return 0;
}else if(n==1){
return 0;
}else if(n==2){
return 1;
}else{
return trb(n-1)+trb(n-2)+trb(n-3);
}
}
int main(void){
int a;
return 0;
}
I2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgdHJiKGludCBuKXsKCWlmKG49PTApewoJCXJldHVybiAwOwoJfWVsc2UgaWYobj09MSl7CgkJcmV0dXJuIDA7Cgl9ZWxzZSBpZihuPT0yKXsKCQlyZXR1cm4gMTsKCX1lbHNlewoJCXJldHVybiB0cmIobi0xKSt0cmIobi0yKSt0cmIobi0zKTsKCX0KfQoKaW50IG1haW4odm9pZCl7CglpbnQgYTsKCXNjYW5mKCIlZCIsJmEpOwoJcHJpbnRmKCIlZCIsdHJiKGEpKTsKCXJldHVybiAwOwp9Cg==