title: Find Sum Modulo K First N Natural Number
signature: findSumModuloKFirstNNaturalNumber(n, k) {
test_code: import 'dart:convert';
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  bool validateSolution(int actual, int expected){
      return actual.toString() == expected.toString();
  }
  
  String driver(n, k, int expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(n, k), expected)){
              return "PASSED";
          }
          return "FAILED";
      }catch(exception_object){
          return exception_object.runtimeType.toString();
      }
  }
  
  int main() {
  
      print("TEST-0...${driver(
          11, 5, 
          21)
      }");
  
      print("TEST-1...${driver(
          36, 69, 
          666)
      }");
  
      print("TEST-2...${driver(
          71, 28, 
          876)
      }");
  
      print("TEST-3...${driver(
          74, 1, 
          0)
      }");
  
      print("TEST-4...${driver(
          66, 84, 
          2211)
      }");
  
      print("TEST-5...${driver(
          38, 14, 
          237)
      }");
  
      print("TEST-6...${driver(
          2, 11, 
          3)
      }");
  
      print("TEST-7...${driver(
          73, 87, 
          2701)
      }");
  
      print("TEST-8...${driver(
          79, 11, 
          388)
      }");
  
      print("TEST-9...${driver(
          30, 55, 
          465)
      }");
  
      return 0;
  }
source_py: def find_sum_modulo_k_first_n_natural_number(N, K):
      ans = 0
      for i in range(1, (N + 1)):
          ans += (i % K)
      return ans
source_cpp: int find_sum_modulo_k_first_n_natural_number(int N, int K) {
    int ans = 0;
    for ( int i = 1;
    i <= N;
    i ++ ) ans += ( i % K );
    return ans;
  }