#include <bits/stdc++.h> using namespace std; typedef signed long long ll; #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define FORR2(x,y,arr) for(auto& [x,y]:arr) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;} template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;} //------------------------------------------------------- ll N; ll V[2020]; void solve() { int i,j,k,l,r,x,y; string s; cin>>N; if(N==1) { cout<<2<<endl; return; } for(k=2;k<=61;k++) { ZERO(V); V[k-1]=1; for(i=k;i<=200;i++) { FOR(j,k) { V[i]+=V[i-1-j]; if(V[i]>N) break; } if(V[i]==N) { cout<<k<<endl; return; } if(V[i]>N) break; } } cout<<-1<<endl; } int main(int argc,char** argv){ string s;int i; if(argc==1) ios::sync_with_stdio(false), cin.tie(0); FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin); cout.tie(0); solve(); return 0; }