#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int my_sum(int x,int y){ int ans=0; for(int i=x;i<=y;i++){ ans+=i; } return ans; } int main(){ cout<<my_sum(1,10); cout<<my_sum(20,30); cout<<my_sum(35,45); return 0; }