#include <stdio.h>
int main(){
int a=1,n;
int sum=0;
while(a<=n){
sum=sum+a;
a=a+1;
}
printf("1から%dの合計は%dです。\n",n
,sum
);
return 0;
}
I2luY2x1ZGUgPHN0ZGlvLmg+CgppbnQgbWFpbigpewogICAgaW50IGE9MSxuOwogICAgaW50IHN1bT0wOwoKICAgIHByaW50Zigi5q2j5pWw44KS5YWl5Yqb44GX44Gm44GP44Gg44GV44GE77yaXG4iKTsKICAgIHNjYW5mKCIlZCIsJm4pOwoKICAgIHdoaWxlKGE8PW4pewogICAgICAgIHN1bT1zdW0rYTsKICAgICAgICBhPWErMTsKICAgIH0KICAgIHByaW50ZigiMeOBi+OCiSVk44Gu5ZCI6KiI44GvJWTjgafjgZnjgIJcbiIsbixzdW0pOwoKICAgIHJldHVybiAwOwp9