#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 sumf(int n,int m) { int sum = 0; for (int i = n; i <= m; i++) { sum += i; } return sum; } int main(){ cout << sumf(1,10) << endl; cout << sumf(20,30) << endl; cout << sumf(35,45); return 0; }