class Solution {
    
    
public:
    int numWays(int n) {
    
    
        if(n ==1 || n == 0) return 1;
        int a = 1, b = 1, i = 0;
        int sum = 0;
        while(i <= n-2){
    
    
            sum =  (a + b) % 1000000007;
            b = a;
            a = sum;
            i++;
        }
        return sum;
    }
};