View Compilation Error

0_0_33518587_27892.cpp: In function 'int main()':
0_0_33518587_27892.cpp:17:29: error: '__gcd' was not declared in this scope
             if(__gcd(i+1,j+1)==1)    {
                             ^
0_0_33518587_27892.cpp:17:29: note: suggested alternative:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:62:0,
                 from 0_0_33518587_27892.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_algo.h:1229:5: note:   'std::__gcd'
     __gcd(_EuclideanRingElement __m, _EuclideanRingElement __n)
     ^