A Fibonacci sequence is calculated by adding the previous two members the sequence,with the first two members being both 1.
F(1) = 1,F(2) = 1,F(3) = 1,F(4) = 1,F(n>4) = F(n - 1) + F(n-2) + F(n-3) + F(n-4)
Your task is to take a number as input,and print that Fibonacci number.

Each line will contain an integers. Process to end of file.

For each case,output the result in a line.

  
  

   
   100
  
  

  
  

   
   4203968145672990846840663646


Note:
No generated Fibonacci number in excess of 2005 digits will be in the test data,ie. F(20) = 66526 has 5 digits.
  
  
  
  


  
  
  
  

   
   
#include<stdio.h>
#include<string.h>
#define MAX 3000+3
char str1[MAX],str2[MAX],c[MAX];
void change(char str1[],char str2[],char sum[])
{
	int len1,len2,i,j,k,z;
	len1=strlen(str1)-1;
	len2=strlen(str2)-1;
	z=0;
	k=0;
	for(i=len1,j=len2;i>=0||j>=0;i--,j--)
	{
		if(i>=0)
			z+=str1[i]-'0';
		if(j>=0)
			z+=str2[j]-'0';
		c[k++]=z%10+'0';
		z=z/10;
	}
	if(z) c[k++]='1';
	i=0;
	for(--k;k>=0;k--)
	sum[i++]=c[k];
	sum[i]='';
}
int main()
{
	int n,i;
	while(scanf("%d",&n)!=EOF)
	{
		char str1[MAX]="1",str2[MAX]="1",str3[MAX]="1",str4[MAX]="1";//相当于题目中的f(1)=1,f(2)=1,f(3)=1,f(4)=1; 
		char f[MAX],f1[MAX],sum1[MAX];
		if(n==0)
		{
			printf("0n");
			continue;
		}
		for(i=4;i<n;i++)
		{
			change(str1,str2,f);
			change(str3,str4,f1);
			change(f,f1,sum1);
			strcpy(str1,str2);
			strcpy(str2,str3);
			strcpy(str3,str4);
			strcpy(str4,sum1);
		}
		printf("%sn",str4);
	}
	return 0;
}