class Solution {
public int fib(int n) {
if(n <= 1) return n;
int [] dp = new int[n+1];
dp[0] = 0;
dp[1] = 1;
for(int index = 2; index <= n ; index++){
dp[index] = dp[index-1] + dp[index-2];
}
return dp[n];
}
}