View Compilation Error

0_0_21112737_7752.cpp: In function 'int main()':
0_0_21112737_7752.cpp:170:10: error: conflicting declaration 'bool first'
     bool first=true;
          ^
0_0_21112737_7752.cpp:37:11: note: previous declaration as 'int first'
 #define x first
           ^
0_0_21112737_7752.cpp:169:11: note: in expansion of macro 'x'
     int m,x,y,a,b,c;
           ^