./test.cpp: In function 'int main(int, const char**)':
./test.cpp:8:22: warning: format '%f' expects argument of type 'double', but argument 2 has type 'int' [-Wformat=]
printf("%.4f\n",a);
^
./test.cpp:8:23: error: expected '}' at end of input
printf("%.4f\n",a);
^