long getWays(int n, vector<long> c) {
    vector<long> dp(n+1,0);
    dp[0]=1;
    int cs = c.size();
    
     for (int i = 0; i < cs; i++) {
         int coin = c[i];
         for (int j = coin; j <= n; j++) {
             dp[j] += dp[j-coin];
         }
     }
     
    return dp[n];
}