Main.cc: In function ‘int main()’:
Main.cc:5:29: error: expected primary-expression before ‘;’ token
int n=b*1000+c*100+d*10+;
^
Main.cc:4:34: warning: unused variable ‘e’ [-Wunused-variable]
int b=a%10,c=a/10%10,d=a/100%10,e=a/1000%10;
^