Main.cc: In function 'int main()':
Main.cc:13:2: error: expected primary-expression before 'else'
else if(a>='0'&&a<='9'){
^
Main.cc:5:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%c",&a);
^