diff --git a/5.Infix-Postfix.c b/5.Infix-Postfix.c
new file mode 100644
index 0000000..9274151
--- /dev/null
+++ b/5.Infix-Postfix.c
@@ -0,0 +1,82 @@
+#include<stdio.h>
+int top=-1;
+char stack[20];
+
+void push(char x)
+{
+    stack[++top]=x;
+}
+char pop()
+{
+    if(top==-1)
+    {
+        return -1;
+    }
+    else
+    {
+        return stack[top--];
+    }
+}
+int priority(char x)
+{
+    int p;
+    switch(x)
+    {
+    case '(':
+        p=0;
+        break;
+    case ')':
+        p=0;
+        break;
+    case '+':
+    case '-':
+        p=1;
+        break;
+    case '/':
+    case '*':
+        p=2;
+        break;
+    }
+    return p;
+}
+void main()
+{
+    char *e,exp[20],ch;
+    printf("Enter infix expression\n");
+    scanf("%s",exp);
+    e=exp;
+    push('(');
+    while(*e!='\0')
+    {
+        if(isalpha(*e))
+        {
+            printf("%c",*e);
+        }
+        else if(*e=='(')
+        {
+            push(*e);
+        }
+        else if(*e==')')
+        {
+            while(ch=pop()!='(')
+                printf("%c",ch);
+        }
+        else
+        {
+            while(priority(stack[top])>priority(*e))
+            
+                printf("%c",*e);
+                push(*e);
+            
+        }
+        e++;
+            
+        
+    }
+    
+    while(top>0)
+    {
+        printf("%c",pop());
+        
+    }
+}