PTA兔子衍生

#include<stdio.h>
int main()
{
	int i = 0, j = 1;
	int n;
	int k;
	scanf("%d", &n);
	int sum=0;
    if(n==1){
        k=1;
        printf("%d",k);
    }
    else{
        k=2;
	while (1) {
		sum = i + j;
		i = j;
		j = sum;
		if (sum >= n) {
			printf("%d", k);
			break;
		}
		k++;
	}
    }
}