View Compilation Error

0_0_16013284_20855.cpp: In function 'int main()':
0_0_16013284_20855.cpp:10:3: error: expected initializer before 'int'
   int n,i,j;
   ^
0_0_16013284_20855.cpp:11:18: error: 'n' was not declared in this scope
   scanf("%d%*c",&n);
                  ^
0_0_16013284_20855.cpp:12:7: error: 'i' was not declared in this scope
   for(i=1;i<=n;i++)
       ^
0_0_16013284_20855.cpp:14:9: error: 'a' was not declared in this scope
    gets(a);
         ^
0_0_16013284_20855.cpp:15:8: error: 'j' was not declared in this scope
    for(j=0;j<=strlen(a)-1;j+=2) 
        ^