View Code of Problem 23

#include <stdio.h>

int main(void)
{
    long long n,i,br[91]={0},sr[91] = {0},sum[91] = {0};
    sr[1]= 1, br[1] = 0,sum[1] = 1;
    br[2] = 1,sr[2] = 1, sum[2] = 2;
    for(i = 3;i <= 90;i++)
    {
        br[i] = br[i - 1] + sr[i - 1];
        sr[i] = br[i - 1];
        sum[i] = br[i] + sr[i];
    }
    while(scanf("%lld",&n) != EOF && n)
    {
        printf("%lld\n",sum[n]);
    }
    return 0;

}