View Compilation Error

0_0_30417528_27396.cpp: In function 'int main()':
0_0_30417528_27396.cpp:12:9: error: expected ';' before 'int'
         int a[n+1][n+1];
         ^
0_0_30417528_27396.cpp:15:22: error: 'a' was not declared in this scope
                 cin>>a[i][j];
                      ^
0_0_30417528_27396.cpp:18:22: error: 'a' was not declared in this scope
             dp[n][i]=a[n][i];
                      ^
0_0_30417528_27396.cpp:21:51: error: 'a' was not declared in this scope
             dp[i][j]=max(dp[i+1][j],dp[i+1][j+1])+a[i][j];
                                                   ^