#include<stdio.h>
#include<string.h>
void add(char a[],char b[],char back[]);
main()
{
	char a[65] = "1312312321";
	char b[65] = "123123123123";
	char back[130] = "";
	add(a,b,back);
	printf("%s",back);
}
void add(char a[],char b[],char back[])
{
	int i,j,k,up,x,y,z,l;
	char *c;
	if (strlen(a)>strlen(b)) 
		l=strlen(a)+2; 
	else 
		l=strlen(b)+2;
	c=(char *) malloc(l*sizeof(char));
	i=strlen(a)-1;
	j=strlen(b)-1;
	k=0;up=0;
	while(i>=0||j>=0)
	{
		if(i<0)
			x='0';
		else 
			x=a[i];
		if(j<0)
			y='0';
		else 
			y=b[j];
		z=x-'0'+y-'0';
		if(up) 
			z+=1;
		if(z>9) 
		{
			up=1;
			z%=10;
		}
		else 
			up=0;
		c[k++]=z+'0';
		i--;
		j--;
	}
	if(up) 
		c[k++]='1';
	i=0;
	c[k]='\0';
	for(k-=1;k>=0;k--)
		back[i++]=c[k];
	back[i]='\0';
}