NYOJ480 Fibonacci Again!

水。

#include <cstdio>
#include <cmath>

bool f(int n){
	int t = (int)sqrt(n);
	for(int i = 2; i <= t; ++i)
		if(n % i == 0) return 0;
	return 1;
}

int main(){
	int a[30] = {0, 3, 7}, i;
	for(i = 3; i != 30; ++i)
		a[i] = a[i - 1] + a[i - 2];
	while(scanf("%d", &i), i != -1)
		printf(f(a[i]) == 0 ? "No\n" : "Yes\n");
	return 0;
}