What is the output of the following program?#includeint max_num(int a,int b){     if(a> b) return a;     return b;}int maximum_subarray_sum(int *arr, int len){     int sum[len], idx;     sum[0] = arr[0];     for(idx = 1; idx < len; idx++) sum[idx] = max_num(sum[idx - 1] + arr[idx], arr[idx]);     int mx = sum[0];     for(idx = 0; idx < len; idx++) if(sum[idx] > mx)    mx =sum[idx];     return mx;}int main(){     int arr[] = {-20, 23, 10, 3, -10, 11, -5},len = 7;     int ans = maximum_subarray_sum(arr, len);     printf("%d",ans);     return 0;}