Go: package main

import "fmt"

func roundUp100(dept float64) float64 {
	iDept := int(dept)
	if iDept-(iDept/1000*1000) != 0 {
		iDept = ((iDept / 1000) + 1) * 1000
	}
	return float64(iDept)
}

func main() {
	var week int
	fmt.Scan(&week)

	dept := 100000.0
	for i := 0; i < week; i++ {

		dept *= 1.05
		dept = roundUp100(dept)
	}

	fmt.Println(dept)
}

//問題文が理解できていない感

C++: #include<iostream>
#include<math.h>
using namespace std;

int main(void){
    int i,n;
    double ans;
    cin >> n;
    ans=100000;
    for(i=0;i<n;i++){
        ans*=1.05;
        ans/=1000;
        ans=int(ans+0.9999999);
        ans=double(ans)*1000;
    }
    //ans*=1000;
    ans=int(ans);
    cout << ans << endl;
    return 0;
}

C++: #include <iostream>
#include <cmath>

using namespace std;

int main() {
    int n, debt = 100000;

    cin >> n;

    for(int i = 0;i < n;i++){
        debt *= 1.05;
    }

    if(debt % 10000 != 0){
        debt = (debt - (debt % 10000)) + 10000;
    }

    cout << debt << endl; 

    return 0;
}

C++: #include <iostream>
using namespace std;
int main(){
    int a=100000,b=0,t=0;
    cin>>t;
    
    if(t==0)cout<<a<<endl;
    else if(t<=100){
      for(int k=1;k<=t;k++){
         b=a*1.05;
         b=(b+900)/1000*1000;
         a=b;
       }
     cout<<a<<endl;
    }
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <algorithm>
#include <sstream>
#include <cmath>
#include <set>
#include <iomanip>
using namespace std;

#define REP(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define REMOVE(Itr,n) (Itr).erase(remove((Itr).begin(),(Itr).end(),n),(Itr).end())
#define PB_VEC(Itr1,Itr2) (Itr1).insert((Itr1).end(),(Itr2).begin(),(Itr2).end())
#define UNIQUE(Itr) sort((Itr).begin(),(Itr).end()); (Itr).erase(unique((Itr).begin(),(Itr).end()),(Itr).end())
#define BOUND(Itr,val) lower_bound((Itr).begin(),(Itr).end(),(val))
typedef long long ll;

int main(){
    
    double i=100000;
    int n; cin>>n;
    REP(j,n){
        i=((double)((ll)(i*1.05)))+1.0;
    }
    
    cout<<(ll)i;
    
    return 0;
}

C++: #include <iostream>
#include <queue>
#include <stack>
#include <vector>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <string>
using namespace std;

long int money = 100000;
int s = 100000;
int a[124],b[124];

int main(){
	int n;
	int tmp;
	cin>>n;
	//while(n!=0){
		money = 100000;
	for(int i=0;i<n;i++){
		money*=1.05;
		//if(i==n-1) cout << "\nbefore  \n" << money <<"\nafter"<<endl;
		if(i==24){
			tmp = money/100;
			//cout<<tmp<<endl;
		}
		tmp = money%1000;
		if(tmp!=0){
			money/=1000;
			money++;
			money*=1000;
			
		}
		b[i+1] = money;
		//if(i==n-1)	cout << money << endl;
	}
		//cout<<b[n]<<endl;
		
		
 
    
    //scanf("%d",&n);
 
 
    for(int i=0;i<n;i++){
        if(int(s*1.05)%1000==0){
            s=int(s*1.05);
        }else{
            s= int(s*1.05) + (1000- int(s*1.05) % 1000);
        }
    	a[i+1] = s;
    }
    //printf("%d\n",s);
	
		for(int i=0;i<n;i++)
		if(a[i+1]!=b[i+1])
			cout<<i+1<<" a = "<<a[i+1]<<" b = "<<b[i+1]<<endl;
	//cout << money << endl;
		//cin >> n;
	//}
	return 0;
}

C++: #include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <queue>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <complex>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <stdio.h>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<double> VEC;
typedef vector<VEC> MAT;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<int, PII> TIII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
//container util

//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define MT(a,b,c) MP(a, MP(b, c))
#define T1 first
#define T2 second.first
#define T3 second.second.first
#define T4 second.second.second

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define EPS 1.0e-9

int main(){
	LL p = 100;
	int n;
	cin>>n;
	REP(i,n){
		if(p%100)p+=p/20+1;
		else p+=p/20;
	}
	p*=1000;
	cout << p<< endl;
	return 0;
}

C++: #include <iostream>
#include <cstring>
#include <cstdio>

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,j) FOR(i,0,j)

const int MAX_D = 130;

struct Integer{
    Integer(int i = 0){
        memset(digits, 0, sizeof(digits));
        n = 0;

        while(i > 0){
            digits[n++] = i % 10;
            i /= 10;
        }
    }
    Integer(const std::string& s){
        memset(digits, 0, sizeof(digits));
        n = 0;

        bool f = false;
        for(int j=(int)s.size()-1;j>=0;j--){
            if(!std::isdigit(s[j])){continue;}

            if(s[j] != '0'){
                digits[n++] = s[j] - '0';
                f = true;
            }else if(f){
                digits[n++] = s[j] - '0';
            }
        }
    }
    int digits[MAX_D], n;
};

Integer operator*(const Integer& lhs, const Integer& rhs){
    Integer res;
    for(int i=0;i<MAX_D;i++){
        for(int j=0;j<MAX_D;j++){
            if(i + j >= MAX_D){continue;}
            int x = lhs.digits[i] * rhs.digits[j] + res.digits[i+j];
            res.digits[i+j] = x % 10;
            if(i + j + 1 < MAX_D){
                res.digits[i+j+1] += x / 10;
            }
        }
    }

    return res;
}

Integer operator+(const Integer& lhs, const Integer& rhs){
    Integer res;
    for(int i=0;i<MAX_D;i++){
        int x = lhs.digits[i] + rhs.digits[i] + res.digits[i];
        res.digits[i] = x % 10;
        if(i+1 < MAX_D){
            res.digits[i+1] = x / 10;
        }
    }

    return res;
}

int main(){
    int N;
    std::cin >> N;

    Integer x(100000), k1(105), k2(1000);
    REP(i, N){
        x = x * k1;
        
        FOR(j, 2, MAX_D){
            x.digits[j-2] = x.digits[j];
        }

        if(x.digits[0] || x.digits[1] || x.digits[2]){
            REP(i, 3){x.digits[i] = 0;}
            x = x + k2;
        }
    }

    bool f = false;
    for(int i=MAX_D-1;i>=0;i--){
        if(x.digits[i] != 0){
            f = true;
        }

        if(f){
            printf("%d", x.digits[i]);
        }
    }
    puts("");
}

C++: #include <iostream>
#include <cmath>

int main() {
	double m = 100;
	int n;

	std::cin >> n;
	for (int i = 0; i < n; ++i) {
		m *= 1.05;
		m = std::ceil(m);
	}
	std::cout << m * 1000 << std::endl;
	return 0;
}