>>293
#include <stdio.h>
#define xx for
#define xxx int
#define xxxx char
#define xxxxxx void
xxxxxx xxxxx(xxxx **x,xxxx y,xxx *c){*c-=y-'0';}
xxx main(){xxx n=0;xxxx buf[21],*p=gets(buf);xx(;*p;++p){if(*p=='-'){xxxxx(&p,*++p,&n);continue;}n+=*p-'0';}printf("%d",n);}

>>290をCに勝手に修正