POJ 2030

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string.h>
using namespace std;

class STRS{
public:
	char str[100];
	void operator=(STRS b){
		strcpy(str,b.str);
	}
	STRS operator+(char b){
		STRS tmp;
		strcpy(tmp.str,str);
		int leng=strlen(tmp.str);
		if(tmp.str[0]==‘0‘){
			tmp.str[0]=b;
			tmp.str[1]=‘\0‘;
		}
		else{
			tmp.str[leng]=b;
			tmp.str[leng+1]=‘\0‘;
		}
		return tmp;
	}
	bool operator >(STRS b){
		int al=strlen(str); int bl=strlen(b.str);
		if(al>bl) return true;
		else if(bl>al) return false;
		for(int i=0;i<al;i++){
			if(str[i]>b.str[i])
			return true;
			else if(str[i]<b.str[i])
			return false;
		}
		return false;
	}
	void initial(){
		strcpy(str,"0");
	}
};

STRS gp[100],dp[100][100],answer;
int n,m;

int main(){
	STRS tmpt;
	while(scanf("%d%d",&m,&n)!=EOF){
		if(n==0&m==0) break;
		for(int i=0;i<=n;i++)
		for(int j=0;j<=m;j++)
		dp[i][j].initial();
		answer.initial();
		for(int i=1;i<=n;i++)
		scanf("%s",gp[i].str+1);
		for(int i=1;i<=n;i++){
			for(int j=1;j<=m;j++){
				if(gp[i].str[j]>=‘0‘&&gp[i].str[j]<=‘9‘){
					dp[i][j]=dp[i][j]+gp[i].str[j];
					tmpt=dp[i][j-1]+gp[i].str[j];
					if(tmpt>dp[i][j])
					dp[i][j]=tmpt;
					tmpt=dp[i-1][j]+gp[i].str[j];
					if(tmpt>dp[i][j])
					dp[i][j]=tmpt;
					if(dp[i][j]>answer)
					answer=dp[i][j];
				}
			}
		}
		printf("%s\n",answer.str);
	}
	return 0;
}