>>143
int myatoi(char *s)
{
int r;
sscanf(s,"%d",&r);
return r;
}

char* sign(char *s)
{
int r,e;
e = sscanf(s,"%d",&r);
if(e == 0)
return "0";
else if(r < 0)
return "?1";
else
return "1";
}

int check(char *s)
{
int r,e;
e = sscanf(s,"%d",&r);
return e == 0 ? 0 : 1;
}