View Code of Problem 23

#include<stdio.h>
int main(){
	int M;
  	long int a[90];
  	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&&M>0){
      	printf("%ld\n",a[M-1]);
  }
}