View Compilation Error

0_0_40049637_31603.cpp: In function 'int down(int, int)':
0_0_40049637_31603.cpp:12:46: error: 'y2' was not declared in this scope; did you mean 'y'?
   12 |     return dp[yy][1-use]-val[yy]+sum[yy]*sum[y2]-(dp[y][1-use]-val[y]+sum[y]*sum[y]);
      |                                              ^~
      |                                              y