C++ :

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
	int a,b,c;
	cin>>a>>b>>c;
	double sum=0;
	for (int i=1; i<=a; i++) sum+=i;
	for (int i=1; i<=b; i++) sum+=i*i;
	for (int i=1; i<=c; i++) sum+=1.0/i;
	printf("%.2lf\n",sum);
	return 0;
}

Python :

# coding=utf-8
import sys
def main():
    while True:
        a,b,c=sys.stdin.readline().strip().split(' ')
        a=int(a)
        b=int(b)
        c=int(c)
        sum=0
        for i in range(1,a+1):
            sum+=i
        sum1=0
        for i in range(1,b+1):
            sum1+=i**2
        sum2=0
        for i in range(1,c+1):
            sum2+=1/i
        sum3=round(sum+sum1+sum2,2)
        print(sum3)
if __name__ == '__main__':
    main()