View Compilation Error

0_0_15994593_10453.cpp: In function 'int main()':
0_0_15994593_10453.cpp:50:28: error: 'x' was not declared in this scope
            while(now > i &&x[now] + x[i] >= mod) now--;
                            ^
0_0_15994593_10453.cpp:51:39: error: 'x' was not declared in this scope
            if (now > i) ans = max(ans,x[now]+x[i]);
                                       ^
0_0_15994593_10453.cpp:52:39: error: 'x' was not declared in this scope
            if (i!=n-1) ans = max(ans,(x[i]+x[n-1])%mod); 
                                       ^