My solver found 351 solutions without repeating items. But the article says there are 279. What is wrong?

  #include <stdio.h>
  
  #define N_ITEMS 21
  
  int prices[] = {122,275,185,597,647,216,713,457,146,518,316,489,711,
                  645,477,804,671,231,621,98,87};
  
  int sol[N_ITEMS] = {0};
  
  void show_sol(void) {
    printf("[");
    for(int i = 0; i < N_ITEMS; i++)
      printf("%d%c", sol[i], i != N_ITEMS - 1 ? ',' : '\0');
    printf("]\n");
  }
  
  void solve(int limit, int depth)
  {
    if(depth == N_ITEMS)
      return;
  
    if(limit == 0){
      show_sol();
      return;
    }
  
    solve(limit, depth+1);
    sol[depth]++;
    limit -= prices[depth];
    solve(limit, depth+1);
  
    sol[depth] = 0;
  }
  
  int main(void) {
    solve(4394, 0);
    return 0;
  }