View Code of Problem 23

#include<stdio.h>
int main()
{
	int a[90],m;
  	a[0]=1,a[1]=2;
  	for(int i=2;i<90;i++)
        {
        	a[i]=a[i-1]+a[i-2];
        }
  	while(scanf("%d",&m)!=EOF)
        {
        	printf("%d\n",a[m-1]);
        }
  	return 0;
}