class Solution {
public:
int Fibonacci(int n) {
if(n == 0)
return 0;
if(n == 1)
return 1;
int result[3] = {0,1,1};
for(int i = 3; i <= n; i++){
result[0] = result[1];
result[1] = result[2];
result[2] = result[0] + result[1];
}
return result[2];
}
};