int Zadacha_1(int A, int N){
      int result = 1 - A;
      bool min = false;
      for(int i = 2; i<N; i++){
          if(min){
              result = result - ( A * i );
              min = false;   
          }
          else{
              result = result + ( A * i );
              min = true;   
          }
      }
      return result;
}

//Без math.h
int Zadacha_2(int A, int N){
      int r = A;
      for(int i=0; i<N; i++) r = r * N;
      return r;
}