eclipse console dispalying large numbers when finding sum of odd numbers from 1 to 5 in C

Question

#include <stdio.h>
#include <stdlib.h>

int main(void) {
    int n,i,sum;
    setbuf(stdout,NULL);
    printf("enter  a limit"); /* prints !!!Hello World!!! */
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        if(i%2 != 0){
            sum=sum+i;
        }
    }
    printf("sum is %d",sum);
    return EXIT_SUCCESS;
}

Program to find sum of odd numbers from 1 to a limit. Whenever I run this program the output shown is 6 or 7 digit numbers. Please help me solve this. Thanks in advance!!