View Compilation Error

0_0_15573637_29167.cpp: In function 'int main()':
0_0_15573637_29167.cpp:21:13: error: redeclaration of 'int len'
         int len,i;
             ^
0_0_15573637_29167.cpp:9:14: note: 'int len' previously declared here
          int len,i;
              ^
0_0_15573637_29167.cpp:21:17: error: redeclaration of 'int i'
         int len,i;
                 ^
0_0_15573637_29167.cpp:9:18: note: 'int i' previously declared here
          int len,i;
                  ^