string intToRoman(int num) {

         string res;

         char a[]={'I','X','C','M'};

         char b[]={'V','L','D'};

         int i=,ld=,n=;

         while(i>=)

         {

             ld=num/n;

             num%=n;

             n/=;

             switch(ld)

             {

                 case :break;

                 case :{res+=a[i];break;}

                 case :{res=res+a[i]+a[i];break;}

                 case :{res=res+a[i]+a[i]+a[i];break;}

                 case :{res=res+a[i]+b[i];break;}

                 case :{res=res+b[i];break;}

                 case :{res=res+b[i]+a[i];break;}

                 case :{res=res+b[i]+a[i]+a[i];break;}

                 case :{res=res+b[i]+a[i]+a[i]+a[i];break;}

                 case :{res=res+a[i]+a[i+];break;}

                 default :break;

             }

             i--;

         }

         return res;

     }