View Compilation Error

0_0_36009331_29521.cpp: In function 'long long int kuai(int)':
0_0_36009331_29521.cpp:21:5: error: '__64int' was not declared in this scope
     __64int b;
     ^
0_0_36009331_29521.cpp:23:9: error: 'b' was not declared in this scope
         b=2;
         ^
0_0_36009331_29521.cpp:25:9: error: 'b' was not declared in this scope
         b=kuai(a-1)+2*2*(a-1)+1;
         ^
0_0_36009331_29521.cpp:26:12: error: 'b' was not declared in this scope
     return b;
            ^