View Compilation Error

0_0_14503092_13007.cpp: In function 'int main()':
0_0_14503092_13007.cpp:35:61: error: 'mod' was not declared in this scope
                 dp[i][j]=(dp[i-1][j]+dp[i-1][(j-a[i]+9)%9])%mod;
                                                             ^