two int for loop

/* standard libraries */
#include <iostream>
#include <math.h>

using namespace std;
/* main program */
int main()
{
 /*variables*/
 int  i,stop;
 char a,b;
 float number,sum;


  for (;;)
  {
     cout<<"Enter a number:";
     cin>>number;

     if (number!=0.0)
     {
       sum+=number;
     }

     else (a==0||b==0)
     {
        cout<<"type 'stop' to finish."<<endl;
       cin>>stop;

       }

     cout<<"sum="<<sum;

   }
  }

return 0;
}