忘记题目了

#include<stdio.h>int fnn(int i);void main(){int n,s,m;s=0;scanf("%d",&n);if(n>0){    for(m=1;;m++)    {    s+=fnn(m);    if(s>=n)    break;    else continue;    }    m--;    printf("%d",m);}else printf("请输入一个正整数");}int fnn(int i){return (i*i*i);}