View Compilation Error

0_0_36569477_788.cpp: In function 'int main()':
0_0_36569477_788.cpp:154:12: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
    printf(1);// << 1 << '\n';
            ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cstdio:42:0,
                 from 0_0_36569477_788.cpp:1:
GCC4.9.2/x86_64-w64-mingw32/include/stdio.h:378:15: note: initializing argument 1 of 'int printf(const char*, ...)'
   int __cdecl printf(const char * __restrict__ _Format,...);
               ^