View Compilation Error

0_0_25636748_13993.cpp: In function 'int main()':
0_0_25636748_13993.cpp:2:11: error: 'first' was not declared in this scope
 #define x first
           ^
0_0_25636748_13993.cpp:78:20: note: in expansion of macro 'x'
    scanf("%d%d%d",&x[i],&y[i],&w[i]);
                    ^
0_0_25636748_13993.cpp:3:11: error: 'second' was not declared in this scope
 #define y second
           ^
0_0_25636748_13993.cpp:78:26: note: in expansion of macro 'y'
    scanf("%d%d%d",&x[i],&y[i],&w[i]);
                          ^