/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
	}
}

LyogcGFja2FnZSB3aGF0ZXZlcjsgLy8gZG9uJ3QgcGxhY2UgcGFja2FnZSBuYW1lISAqLwoKaW1wb3J0IGphdmEudXRpbC4qOwppbXBvcnQgamF2YS5sYW5nLio7CmltcG9ydCBqYXZhLmlvLio7CgovKiBOYW1lIG9mIHRoZSBjbGFzcyBoYXMgdG8gYmUgIk1haW4iIG9ubHkgaWYgdGhlIGNsYXNzIGlzIHB1YmxpYy4gKi8KY2xhc3MgSWRlb25lCnsKCXB1YmxpYyBzdGF0aWMgdm9pZCBtYWluIChTdHJpbmdbXSBhcmdzKSB0aHJvd3MgamF2YS5sYW5nLkV4Y2VwdGlvbgoJewoJCS8vIHlvdXIgY29kZSBnb2VzIGhlcmUKCX0KfQ==

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

#include <stdio.h>

int main() {
    int a, b, sum = 0, i;

    // 二つの整数を読み込む
    printf("1つ目の整数を入力: ");
    scanf("%d", &a);
    printf("2つ目の整数を入力: ");
    scanf("%d", &b);

    // 小さい方をmin、大きい方をmaxに
    int min = (a < b) ? a : b;
    int max = (a > b) ? a : b;

    i = min;
    do {
        sum += i;
        i++;
    } while (i <= max);

    printf("合計: %d\n", sum);

    return 0;
}