01  #include<stdio.h>
02  
03  int lcm(int,int);
04  
05  int main()
06   {
07    int x,y=1;
08  
09    printf("Enter Numbers to find LCM ( press 0 to exit) : ");
10  
11    while(1)
12    {
13     scanf("%d",&x);
14  
15     if(x<1)
16      break;
17     else if(x>y)
18     y = lcm(x,y);
19     else
20     y = lcm(y,x);
21     }
22  
23    printf("LCM is %d",y);
24  
25   return 0;
26   }
27  
28  int lcm(int x,int y)
29  {
30   int temp = x;
31   
32   while(1)
33   {
34    if(temp % y == 0 && temp % x == 0)
35    break;
36    temp++;
37   }
38   return temp;
39  }

 OUTPUT :
 
 Enter numbers to find LCM (press 0 to exit) :
 
 10
 15
 20
 0
 
 LCM is 60