zoj 2060 Fibonacci Again

#include<stdio.h>
int a[1000005];
/*int solve(int n) {
while(n--) {}
}*/
int main() {
#ifndef ONLINE_JUDGE
freopen("in.txt","r",stdin);
#endif
int i,n;
a[0]=7;a[1]=11;
for(i=2;i<=1000000;i++) {
//a[i-1]%=3;
a[i]=((a[i-1]%3)+(a[i-2]%3))%3;
}
while(scanf("%d",&n)!=EOF) {
//solve(n);
if (a
==0) printf("yes\n");
else printf("no\n");
}
return 0;
}