View Compilation Error

0_0_27685025_32486.cpp: In function 'int shu(char)':
0_0_27685025_32486.cpp:5:2: error: 'nbsp' was not declared in this scope
     return (a-'0');
  ^
0_0_27685025_32486.cpp: In function 'int main()':
0_0_27685025_32486.cpp:8:2: error: 'nbsp' was not declared in this scope
     char a[1000],b[1000];
  ^