/in/foo.cc: In function 'bool check(int)':
/in/foo.cc:49:6: warning: unused variable 'u' [-Wunused-variable]
  int u,v,ta;
      ^
/in/foo.cc:49:8: warning: unused variable 'v' [-Wunused-variable]
  int u,v,ta;
        ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:83:8: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",ans);
  ~~~~~~^~~~~~~~~~
/in/foo.cc:24:20: warning: 'ma' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return x/gcd(x,y)*y;
                    ^
/in/foo.cc:63:9: note: 'ma' was declared here
  int mi,ma;
         ^~
/in/foo.cc:75:15: warning: 'mi' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int l=1,r=lcm(-mi,ma),mid,ans;
            ~~~^~~~~~~~