#include <stdio.h>
#include <conio.h>
#include <string.h>


char* CongSoNguyenLon(char *a, char *b)
{
	int n,n1,n2,t;
	n1=strlen(a);
	n2=strlen(b);
	if(n1>n2)
		n=n1;
	else
		n=n2;
	char *tong=new char[n+2];
	tong[n-1]='\0';
	int nho=0;
	for(int i=1;i<=n;i++)
	{
		if(i<=n1 && i<=n2)
			t=a[n1-i]-'0'+b[n2-i]-'0';
		else
			if(i>n1)
				t=b[n2-i]-'0';
			else
				t=a[n1-i]-'0';
		t=t+nho;
		if(t>9)
			nho=1;
		else
			nho=0;
		tong[n-i+1]=t%10+'0';
	}
	tong[0]=nho+'0';
	return tong;
}
int main()
{
	char *a,*b,*tong;
	a=new char;
	b=new char;
	printf("Nhap so a:");
	gets(a);
	printf("Nhap so b:");
	gets(b);
	tong = CongSoNguyenLon(a,b);
	printf("Tong = %s",tong);
	getch();
	return 0;
}