#include <stdio.h>
#include <math.h>
#include <stdlib.h>

unsigned long base10;
int oldbase;
char c[100];
unsigned long rest,erg;
int pos=0;
int i;

int main()
{
 base10=0;
 oldbase=36;
 for(i=0;i<100;c[i++]=0);
 
 printf("Altes Zahlensystem:");
 scanf("%d",&oldbase);

 printf("Zahl im %der-System:",oldbase);
 scanf("%s",&c);
 pos=0;
 while(c[pos++]);
 pos--;
 int len=pos-1;
 while(pos--)
 {
  if(isdigit(c[len-pos]))
  {
   base10 = base10 + (unsigned long)( (double)(c[len-pos]-'0') * ( pow( (double)oldbase,(double)pos ) ) ) ;
  printf("-N-DEBUG: base10:%d, c:%c, pos:%d\n",base10,c[pos],pos);
  }
  else
  {
   base10 = base10 + (unsigned long)( ((double)(c[len-pos]-'A')+10) * ( pow( (double)oldbase,(double)pos ) ) );
  printf("-A-DEBUG: base10:%d, c:%c, pos:%d\n",base10,c[pos],pos);
  }
 }
 printf("Zahl im 10er-system:%d\n",base10);
}